use == and != to enable handling null/undefined

lib/runtime/dart/_interceptors.js

 var _interceptors;
 (function(exports) {
   'use strict';
   class Interceptor extends core.Object {
     Interceptor() {
     }
     ['=='](other) {
       return core.identical(this, other);
     }
     get hashCode() {
@@ skipping 77 matching lines @@
       insertAll(index, iterable) {
         this.checkGrowable('insertAll');
         _internal.IterableMixinWorkaround.insertAllList(this, index, iterable);
       }
       setAll(index, iterable) {
         this.checkMutable('setAll');
         _internal.IterableMixinWorkaround.setAllList(this, index, iterable);
       }
       removeLast() {
         this.checkGrowable('removeLast');
-        if (this.length === 0)
+        if (this.length == 0)
           throw new core.RangeError.value(-1);
         return dart.as(this.pop(), E);
       }
       remove(element) {
         this.checkGrowable('remove');
         for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
           if (dart.equals(this.get(i), element)) {
             this.splice(i, 1);
             return true;
           }
@@ skipping 17 matching lines @@
           this.add(e);
         }
       }
       clear() {
         this.length = 0;
       }
       forEach(f) {
         let length = this.length;
         for (let i = 0; dart.notNull(i) < dart.notNull(length); i = dart.notNull(i) + 1) {
           f(dart.as(this[i], E));
-          if (length !== this.length) {
+          if (length != this.length) {
             throw new core.ConcurrentModificationError(this);
           }
         }
       }
       map(f) {
         return _internal.IterableMixinWorkaround.mapList(this, f);
       }
       join(separator) {
         if (separator === void 0)
           separator = "";
@@ skipping 37 matching lines @@
       }
       sublist(start, end) {
         if (end === void 0)
           end = null;
         _js_helper.checkNull(start);
         if (!(typeof start == 'number'))
           throw new core.ArgumentError(start);
         if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(this.length)) {
           throw new core.RangeError.range(start, 0, this.length);
         }
-        if (end === null) {
+        if (end == null) {
           end = this.length;
         } else {
           if (!(typeof end == 'number'))
             throw new core.ArgumentError(end);
           if (dart.notNull(end) < dart.notNull(start) || dart.notNull(end) > dart.notNull(this.length)) {
             throw new core.RangeError.range(end, start, this.length);
           }
         }
-        if (start === end)
+        if (start == end)
           return new core.List$(E).from([]);
         return new JSArray.markGrowable(this.slice(start, end));
       }
       getRange(start, end) {
         return new _internal.IterableMixinWorkaround().getRangeList(this, start, end);
       }
       get first() {
         if (dart.notNull(this.length) > 0)
           return this.get(0);
         throw new core.StateError("No elements");
       }
       get last() {
         if (dart.notNull(this.length) > 0)
           return this.get(dart.notNull(this.length) - 1);
         throw new core.StateError("No elements");
       }
       get single() {
-        if (this.length === 1)
+        if (this.length == 1)
           return this.get(0);
-        if (this.length === 0)
+        if (this.length == 0)
           throw new core.StateError("No elements");
         throw new core.StateError("More than one element");
       }
       removeRange(start, end) {
         this.checkGrowable('removeRange');
         let receiverLength = this.length;
         if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(receiverLength)) {
           throw new core.RangeError.range(start, 0, receiverLength);
         }
         if (dart.notNull(end) < dart.notNull(start) || dart.notNull(end) > dart.notNull(receiverLength)) {
@@ skipping 49 matching lines @@
         return _internal.IterableMixinWorkaround.lastIndexOfList(this, element, start);
       }
       contains(other) {
         for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
           if (dart.equals(this.get(i), other))
             return true;
         }
         return false;
       }
       get isEmpty() {
-        return this.length === 0;
+        return this.length == 0;
       }
       get isNotEmpty() {
         return !dart.notNull(this.isEmpty);
       }
       toString() {
         return collection.ListBase.listToString(this);
       }
       toList(opts) {
         let growable = opts && 'growable' in opts ? opts.growable : true;
         if (growable) {
@@ skipping 85 matching lines @@
     compareTo(b) {
       if (!dart.is(b, core.num))
         throw new core.ArgumentError(b);
       if (this['<'](b)) {
         return -1;
       } else if (this['>'](b)) {
         return 1;
       } else if (dart.equals(this, b)) {
         if (dart.equals(this, 0)) {
           let bIsNegative = b.isNegative;
-          if (this.isNegative === bIsNegative)
+          if (this.isNegative == bIsNegative)
             return 0;
           if (this.isNegative)
             return -1;
           return 1;
         }
         return 0;
       } else if (this.isNaN) {
         if (b.isNaN) {
           return 0;
         }
@@ skipping 87 matching lines @@
       }
       let result = this.toFixed(fractionDigits);
       if (dart.notNull(dart.equals(this, 0)) && dart.notNull(this.isNegative))
         return `-${result}`;
       return result;
     }
     toStringAsExponential(fractionDigits) {
       if (fractionDigits === void 0)
         fractionDigits = null;
       let result = null;
-      if (fractionDigits !== null) {
+      if (fractionDigits != null) {
         _js_helper.checkInt(fractionDigits);
         if (dart.notNull(fractionDigits) < 0 || dart.notNull(fractionDigits) > 20) {
           throw new core.RangeError(fractionDigits);
         }
         result = this.toExponential(fractionDigits);
       } else {
         result = this.toExponential();
       }
       if (dart.notNull(dart.equals(this, 0)) && dart.notNull(this.isNegative))
         return `-${result}`;
       return result;
     }
     toStringAsPrecision(precision) {
       _js_helper.checkInt(precision);
       if (dart.notNull(precision) < 1 || dart.notNull(precision) > 21) {
         throw new core.RangeError(precision);
       }
       let result = this.toPrecision(precision);
       if (dart.notNull(dart.equals(this, 0)) && dart.notNull(this.isNegative))
         return `-${result}`;
       return result;
     }
     toRadixString(radix) {
       _js_helper.checkInt(radix);
       if (dart.notNull(radix) < 2 || dart.notNull(radix) > 36)
         throw new core.RangeError(radix);
       let result = this.toString(radix);
       let rightParenCode = 41;
-      if (result.codeUnitAt(dart.notNull(result.length) - 1) !== rightParenCode) {
+      if (result.codeUnitAt(dart.notNull(result.length) - 1) != rightParenCode) {
         return result;
       }
       return JSNumber[_handleIEtoString](result);
     }
     static [_handleIEtoString](result) {
       let match = /^([\da-z]+)(?:\.([\da-z]+))?\(e\+(\d+)\)$/.exec(result);
-      if (match === null) {
+      if (match == null) {
         throw new core.UnsupportedError(`Unexpected toString result: ${result}`);
       }
       let result = dart.dindex(match, 1);
       let exponent = +dart.dindex(match, 3);
-      if (dart.dindex(match, 2) !== null) {
+      if (dart.dindex(match, 2) != null) {
         result = result + dart.dindex(match, 2);
         exponent = dart.dindex(match, 2).length;
       }
       return core.String['+'](result, core.String['*']("0", exponent));
     }
     toString() {
       if (dart.notNull(dart.equals(this, 0)) && 1 / this < 0) {
         return '-0.0';
       } else {
         return "" + this;
@@ skipping 22 matching lines @@
     }
     ['*'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this * other;
     }
     ['%'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       let result = this % other;
-      if (result === 0)
+      if (result == 0)
         return 0;
       if (dart.notNull(result) > 0)
         return result;
       if (other < 0) {
         return dart.notNull(result) - other;
       } else {
         return dart.notNull(result) + other;
       }
     }
     [_isInt32](value) {
       return (value | 0) === value;
     }
     ['~/'](other) {
       if (false)
         this[_tdivFast](other);
-      if (dart.notNull(this[_isInt32](this)) && dart.notNull(this[_isInt32](other)) && 0 !== other && -1 !== other) {
+      if (dart.notNull(this[_isInt32](this)) && dart.notNull(this[_isInt32](other)) && 0 != other && -1 != other) {
         return this / other | 0;
       } else {
         return this[_tdivSlow](other);
       }
     }
     [_tdivFast](other) {
       return this[_isInt32](this) ? this / other | 0 : (this / other).toInt();
     }
     [_tdivSlow](other) {
       if (!dart.is(other, core.num))
@@ skipping 74 matching lines @@
   let _bitCount = Symbol('_bitCount');
   let _spread = Symbol('_spread');
   let _shru = Symbol('_shru');
   let _shrs = Symbol('_shrs');
   let _ors = Symbol('_ors');
   class JSInt extends JSNumber {
     JSInt() {
       super.JSNumber();
     }
     get isEven() {
-      return this['&'](1) === 0;
+      return this['&'](1) == 0;
     }
     get isOdd() {
-      return this['&'](1) === 1;
+      return this['&'](1) == 1;
     }
     toUnsigned(width) {
       return this['&']((1 << dart.notNull(width)) - 1);
     }
     toSigned(width) {
       let signMask = 1 << dart.notNull(width) - 1;
       return dart.notNull(this['&'](dart.notNull(signMask) - 1)) - dart.notNull(this['&'](signMask));
     }
     get bitLength() {
       let nonneg = this['<'](0) ? dart.notNull(this['unary-']()) - 1 : this;
@@ skipping 78 matching lines @@
     }
     matchAsPrefix(string, start) {
       if (start === void 0)
         start = 0;
       if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(string.length)) {
         throw new core.RangeError.range(start, 0, string.length);
       }
       if (dart.notNull(start) + dart.notNull(this.length) > dart.notNull(string.length))
         return null;
       for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
-        if (string.codeUnitAt(dart.notNull(start) + dart.notNull(i)) !== this.codeUnitAt(i)) {
+        if (string.codeUnitAt(dart.notNull(start) + dart.notNull(i)) != this.codeUnitAt(i)) {
           return null;
         }
       }
       return new _js_helper.StringMatch(start, string, this);
     }
     ['+'](other) {
       if (!(typeof other == 'string'))
         throw new core.ArgumentError(other);
       return this + other;
     }
     endsWith(other) {
       _js_helper.checkString(other);
       let otherLength = other.length;
       if (dart.notNull(otherLength) > dart.notNull(this.length))
         return false;
-      return dart.equals(other, this.substring(dart.notNull(this.length) - dart.notNull(otherLength)));
+      return other == this.substring(dart.notNull(this.length) - dart.notNull(otherLength));
     }
     replaceAll(from, to) {
       _js_helper.checkString(to);
       return dart.as(_js_helper.stringReplaceAllUnchecked(this, from, to), core.String);
     }
     replaceAllMapped(from, convert) {
       return this.splitMapJoin(from, {onMatch: convert});
     }
     splitMapJoin(from, opts) {
       let onMatch = opts && 'onMatch' in opts ? opts.onMatch : null;
       let onNonMatch = opts && 'onNonMatch' in opts ? opts.onNonMatch : null;
       return dart.as(_js_helper.stringReplaceAllFuncUnchecked(this, from, onMatch, onNonMatch), core.String);
     }
     replaceFirst(from, to, startIndex) {
       if (startIndex === void 0)
         startIndex = 0;
       _js_helper.checkString(to);
       _js_helper.checkInt(startIndex);
       if (dart.notNull(startIndex) < 0 || dart.notNull(startIndex) > dart.notNull(this.length)) {
         throw new core.RangeError.range(startIndex, 0, this.length);
       }
       return dart.as(_js_helper.stringReplaceFirstUnchecked(this, from, to, startIndex), core.String);
     }
     split(pattern) {
       _js_helper.checkNull(pattern);
       if (typeof pattern == 'string') {
         return dart.as(this.split(pattern), core.List$(core.String));
-      } else if (dart.notNull(dart.is(pattern, _js_helper.JSSyntaxRegExp)) && _js_helper.regExpCaptureCount(pattern) === 0) {
+      } else if (dart.notNull(dart.is(pattern, _js_helper.JSSyntaxRegExp)) && _js_helper.regExpCaptureCount(pattern) == 0) {
         let re = _js_helper.regExpGetNative(pattern);
         return dart.as(this.split(re), core.List$(core.String));
       } else {
         return this[_defaultSplit](pattern);
       }
     }
     [_defaultSplit](pattern) {
       let result = new core.List$(core.String).from([]);
       let start = 0;
       let length = 1;
       for (let match of pattern.allMatches(this)) {
         let matchStart = dart.as(dart.dload(match, 'start'), core.int);
         let matchEnd = dart.as(dart.dload(match, 'end'), core.int);
         length = dart.notNull(matchEnd) - dart.notNull(matchStart);
-        if (length === 0 && start === matchStart) {
+        if (length == 0 && start == matchStart) {
           continue;
         }
         let end = matchStart;
         result.add(this.substring(start, end));
         start = matchEnd;
       }
       if (dart.notNull(start) < dart.notNull(this.length) || dart.notNull(length) > 0) {
         result.add(this.substring(start));
       }
       return result;
     }
     startsWith(pattern, index) {
       if (index === void 0)
         index = 0;
       _js_helper.checkInt(index);
       if (dart.notNull(index) < 0 || dart.notNull(index) > dart.notNull(this.length)) {
         throw new core.RangeError.range(index, 0, this.length);
       }
       if (typeof pattern == 'string') {
         let other = pattern;
         let otherLength = other.length;
         let endIndex = dart.notNull(index) + dart.notNull(otherLength);
         if (dart.notNull(endIndex) > dart.notNull(this.length))
           return false;
-        return dart.equals(other, this.substring(index, endIndex));
+        return other == this.substring(index, endIndex);
       }
-      return pattern.matchAsPrefix(this, index) !== null;
+      return pattern.matchAsPrefix(this, index) != null;
     }
     substring(startIndex, endIndex) {
       if (endIndex === void 0)
         endIndex = null;
       _js_helper.checkInt(startIndex);
-      if (endIndex === null)
+      if (endIndex == null)
         endIndex = this.length;
       _js_helper.checkInt(endIndex);
       if (dart.notNull(startIndex) < 0)
         throw new core.RangeError.value(startIndex);
       if (dart.notNull(startIndex) > dart.notNull(endIndex))
         throw new core.RangeError.value(startIndex);
       if (dart.notNull(endIndex) > dart.notNull(this.length))
         throw new core.RangeError.value(endIndex);
       return this.substring(startIndex, endIndex);
     }
@@ skipping 50 matching lines @@
         {
           return false;
         }
       }
     }
     static [_skipLeadingWhitespace](string, index) {
       let SPACE = 32;
       let CARRIAGE_RETURN = 13;
       while (dart.notNull(index) < dart.notNull(string.length)) {
         let codeUnit = string.codeUnitAt(index);
-        if (codeUnit !== SPACE && codeUnit !== CARRIAGE_RETURN && !dart.notNull(JSString[_isWhitespace](codeUnit))) {
+        if (codeUnit != SPACE && codeUnit != CARRIAGE_RETURN && !dart.notNull(JSString[_isWhitespace](codeUnit))) {
           break;
         }
         index = dart.notNull(index) + 1;
       }
       return index;
     }
     static [_skipTrailingWhitespace](string, index) {
       let SPACE = 32;
       let CARRIAGE_RETURN = 13;
       while (dart.notNull(index) > 0) {
         let codeUnit = string.codeUnitAt(dart.notNull(index) - 1);
-        if (codeUnit !== SPACE && codeUnit !== CARRIAGE_RETURN && !dart.notNull(JSString[_isWhitespace](codeUnit))) {
+        if (codeUnit != SPACE && codeUnit != CARRIAGE_RETURN && !dart.notNull(JSString[_isWhitespace](codeUnit))) {
           break;
         }
         index = dart.notNull(index) - 1;
       }
       return index;
     }
     trim() {
       let NEL = 133;
       let result = this.trim();
-      if (result.length === 0)
+      if (result.length == 0)
         return result;
       let firstCode = result.codeUnitAt(0);
       let startIndex = 0;
-      if (firstCode === NEL) {
+      if (firstCode == NEL) {
         startIndex = JSString[_skipLeadingWhitespace](result, 1);
-        if (startIndex === result.length)
+        if (startIndex == result.length)
           return "";
       }
       let endIndex = result.length;
       let lastCode = result.codeUnitAt(dart.notNull(endIndex) - 1);
-      if (lastCode === NEL) {
+      if (lastCode == NEL) {
         endIndex = JSString[_skipTrailingWhitespace](result, dart.notNull(endIndex) - 1);
       }
-      if (startIndex === 0 && endIndex === result.length)
+      if (startIndex == 0 && endIndex == result.length)
         return result;
       return result.substring(startIndex, endIndex);
     }
     trimLeft() {
       let NEL = 133;
       let result = null;
       let startIndex = 0;
       if (typeof this.trimLeft != "undefined") {
         result = this.trimLeft();
-        if (result.length === 0)
+        if (result.length == 0)
           return result;
         let firstCode = result.codeUnitAt(0);
-        if (firstCode === NEL) {
+        if (firstCode == NEL) {
           startIndex = JSString[_skipLeadingWhitespace](result, 1);
         }
       } else {
         result = this;
         startIndex = JSString[_skipLeadingWhitespace](this, 0);
       }
-      if (startIndex === 0)
+      if (startIndex == 0)
         return result;
-      if (startIndex === result.length)
+      if (startIndex == result.length)
         return "";
       return result.substring(startIndex);
     }
     trimRight() {
       let NEL = 133;
       let result = null;
       let endIndex = null;
       if (typeof this.trimRight != "undefined") {
         result = this.trimRight();
         endIndex = result.length;
-        if (endIndex === 0)
+        if (endIndex == 0)
           return result;
         let lastCode = result.codeUnitAt(dart.notNull(endIndex) - 1);
-        if (lastCode === NEL) {
+        if (lastCode == NEL) {
           endIndex = JSString[_skipTrailingWhitespace](result, dart.notNull(endIndex) - 1);
         }
       } else {
         result = this;
         endIndex = JSString[_skipTrailingWhitespace](this, this.length);
       }
-      if (endIndex === result.length)
+      if (endIndex == result.length)
         return result;
-      if (endIndex === 0)
+      if (endIndex == 0)
         return "";
       return result.substring(0, endIndex);
     }
     ['*'](times) {
       if (0 >= dart.notNull(times))
         return '';
-      if (times === 1 || this.length === 0)
+      if (times == 1 || this.length == 0)
         return this;
-      if (times !== times >>> 0) {
+      if (!dart.equals(times, times >>> 0)) {
         throw new core.OutOfMemoryError();
       }
       let result = '';
       let s = this;
       while (true) {
-        if ((dart.notNull(times) & 1) === 1)
+        if ((dart.notNull(times) & 1) == 1)
           result = s['+'](result);
         times = dart.as(times >>> 1, core.int);
-        if (times === 0)
+        if (times == 0)
           break;
         s = s;
       }
       return result;
     }
     padLeft(width, padding) {
       if (padding === void 0)
         padding = ' ';
       let delta = dart.notNull(width) - dart.notNull(this.length);
       if (dart.notNull(delta) <= 0)
@@ skipping 22 matching lines @@
         throw new core.ArgumentError(start);
       if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(this.length)) {
         throw new core.RangeError.range(start, 0, this.length);
       }
       if (typeof pattern == 'string') {
         return this.indexOf(pattern, start);
       }
       if (dart.is(pattern, _js_helper.JSSyntaxRegExp)) {
         let re = pattern;
         let match = _js_helper.firstMatchAfter(re, this, start);
-        return match === null ? -1 : match.start;
+        return match == null ? -1 : match.start;
       }
       for (let i = start; dart.notNull(i) <= dart.notNull(this.length); i = dart.notNull(i) + 1) {
-        if (pattern.matchAsPrefix(this, i) !== null)
+        if (pattern.matchAsPrefix(this, i) != null)
           return i;
       }
       return -1;
     }
     lastIndexOf(pattern, start) {
       if (start === void 0)
         start = null;
       _js_helper.checkNull(pattern);
-      if (start === null) {
+      if (start == null) {
         start = this.length;
       } else if (!(typeof start == 'number')) {
         throw new core.ArgumentError(start);
       } else if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(this.length)) {
         throw new core.RangeError.range(start, 0, this.length);
       }
       if (typeof pattern == 'string') {
         let other = pattern;
         if (dart.notNull(start) + dart.notNull(other.length) > dart.notNull(this.length)) {
           start = dart.notNull(this.length) - dart.notNull(other.length);
         }
         return dart.as(_js_helper.stringLastIndexOfUnchecked(this, other, start), core.int);
       }
       for (let i = start; dart.notNull(i) >= 0; i = dart.notNull(i) - 1) {
-        if (pattern.matchAsPrefix(this, i) !== null)
+        if (pattern.matchAsPrefix(this, i) != null)
           return i;
       }
       return -1;
     }
     contains(other, startIndex) {
       if (startIndex === void 0)
         startIndex = 0;
       _js_helper.checkNull(other);
       if (dart.notNull(startIndex) < 0 || dart.notNull(startIndex) > dart.notNull(this.length)) {
         throw new core.RangeError.range(startIndex, 0, this.length);
       }
       return dart.as(_js_helper.stringContainsUnchecked(this, other, startIndex), core.bool);
     }
     get isEmpty() {
-      return this.length === 0;
+      return this.length == 0;
     }
     get isNotEmpty() {
       return !dart.notNull(this.isEmpty);
     }
     compareTo(other) {
       if (!(typeof other == 'string'))
         throw new core.ArgumentError(other);
       return dart.equals(this, other) ? 0 : this < other ? -1 : 1;
     }
     toString() {
@@ skipping 36 matching lines @@
     get(i) {
       return this[_string].codeUnitAt(i);
     }
   }
   // Function _symbolToString: (Symbol) → String
   function _symbolToString(symbol) {
     return _internal.Symbol.getName(dart.as(symbol, _internal.Symbol));
   }
   // Function _symbolMapToStringMap: (Map<Symbol, dynamic>) → dynamic
   function _symbolMapToStringMap(map) {
-    if (map === null)
+    if (map == null)
       return null;
     let result = new core.Map();
     map.forEach((key, value) => {
       result.set(_symbolToString(key), value);
     });
     return result;
   }
   // Function getInterceptor: (dynamic) → dynamic
   function getInterceptor(object) {
     return void 0;
@@ skipping 22 matching lines @@
   function dispatchRecordExtension(record) {
     return record.e;
   }
   // Function dispatchRecordIndexability: (dynamic) → dynamic
   function dispatchRecordIndexability(record) {
     return record.x;
   }
   // Function getNativeInterceptor: (dynamic) → dynamic
   function getNativeInterceptor(object) {
     let record = getDispatchProperty(object);
-    if (record === null) {
-      if (_js_helper.initNativeDispatchFlag === null) {
+    if (record == null) {
+      if (_js_helper.initNativeDispatchFlag == null) {
         _js_helper.initNativeDispatch();
         record = getDispatchProperty(object);
       }
     }
-    if (record !== null) {
+    if (record != null) {
       let proto = dispatchRecordProto(record);
-      if (false === proto)
+      if (dart.equals(false, proto))
         return dispatchRecordInterceptor(record);
-      if (true === proto)
+      if (dart.equals(true, proto))
         return object;
       let objectProto = Object.getPrototypeOf(object);
       if (proto === objectProto) {
         return dispatchRecordInterceptor(record);
       }
       let extension = dispatchRecordExtension(record);
       if (extension === objectProto) {
         let discriminatedTag = proto(object, record);
         throw new core.UnimplementedError(`Return interceptor for ${discriminatedTag}`);
       }
     }
     let interceptor = _js_helper.lookupAndCacheInterceptor(object);
-    if (interceptor === null) {
+    if (interceptor == null) {
       let proto = Object.getPrototypeOf(object);
       if (proto == null || proto === Object.prototype) {
         return _foreign_helper.JS_INTERCEPTOR_CONSTANT(PlainJavaScriptObject);
       } else {
         return _foreign_helper.JS_INTERCEPTOR_CONSTANT(UnknownJavaScriptObject);
       }
     }
     return interceptor;
   }
   dart.copyProperties(exports, {
     get mapTypeToInterceptor() {
       return _foreign_helper.JS_EMBEDDED_GLOBAL('', _js_embedded_names.MAP_TYPE_TO_INTERCEPTOR);
     }
   });
   // Function findIndexForNativeSubclassType: (Type) → int
   function findIndexForNativeSubclassType(type) {
     if (exports.mapTypeToInterceptor == null)
       return null;
     let map = dart.as(exports.mapTypeToInterceptor, core.List);
     for (let i = 0; dart.notNull(i) + 1 < dart.notNull(map.length); i = 3) {
       if (dart.equals(type, map.get(i))) {
         return i;
       }
     }
     return null;
   }
   // Function findInterceptorConstructorForType: (Type) → dynamic
   function findInterceptorConstructorForType(type) {
     let index = findIndexForNativeSubclassType(type);
-    if (index === null)
+    if (index == null)
       return null;
     let map = dart.as(exports.mapTypeToInterceptor, core.List);
     return map.get(dart.notNull(index) + 1);
   }
   // Function findConstructorForNativeSubclassType: (Type, String) → dynamic
   function findConstructorForNativeSubclassType(type, name) {
     let index = findIndexForNativeSubclassType(type);
-    if (index === null)
+    if (index == null)
       return null;
     let map = dart.as(exports.mapTypeToInterceptor, core.List);
     let constructorMap = map.get(dart.notNull(index) + 2);
     let constructorFn = constructorMap[name];
     return constructorFn;
   }
   // Function findInterceptorForType: (Type) → dynamic
   function findInterceptorForType(type) {
     let constructor = findInterceptorConstructorForType(type);
-    if (constructor === null)
+    if (constructor == null)
       return null;
     return constructor.prototype;
   }
   class JSBool extends Interceptor {
     JSBool() {
       super.Interceptor();
     }
     toString() {
       return String(this);
     }
@@ skipping 86 matching lines @@
   exports.findInterceptorForType = findInterceptorForType;
   exports.JSBool = JSBool;
   exports.JSNull = JSNull;
   exports.JSIndexable = JSIndexable;
   exports.JSMutableIndexable = JSMutableIndexable;
   exports.JSObject = JSObject;
   exports.JavaScriptObject = JavaScriptObject;
   exports.PlainJavaScriptObject = PlainJavaScriptObject;
   exports.UnknownJavaScriptObject = UnknownJavaScriptObject;
 })(_interceptors || (_interceptors = {}));