New Analysis Engine translation.

editor/util/plugins/com.google.dart.java2dart/resources/java_core.dart

 library java.core;
 
 import "dart:math" as math;
 import "dart:uri";
 
 class JavaSystem {
   static int currentTimeMillis() {
     return (new DateTime.now()).millisecondsSinceEpoch;
   }
 
@@ skipping 90 matching lines @@
     if (0x61 <= codePoint && codePoint <= 0x66) {
       return 0xA + (codePoint - 0x61);
     }
     return -1;
   }
   static String toChars(int codePoint) {
     throw new UnsupportedOperationException();
   }
 }
 
-class CharBuffer {
+class CharSequence {
   final String _content;
-  CharBuffer(this._content);
-  static CharBuffer wrap(String content) => new CharBuffer(content);
+  CharSequence(this._content);
+  static CharSequence wrap(String content) => new CharBuffer(content);
   int charAt(int index) => _content.codeUnitAt(index);
   int length() => _content.length;
   String subSequence(int start, int end) => _content.substring(start, end);
 }
 
+class CharBuffer extends CharSequence {
+  CharBuffer(String content) : super(content);
+  static CharBuffer wrap(String content) => new CharBuffer(content);
+}
+
 class JavaString {
   static String format(String fmt, List args) {
     return fmt;
   }
 }
 
 /**
  * Very limited printf implementation, supports only %s and %d.
  */
 String _printf(String fmt, List args) {
@@ skipping 302 matching lines @@
       }
     } else if (sb.length > newLength) {
       var s = sb.toString().substring(0, newLength);
       sb = new StringBuffer(s);
     }
   }
   void clear() {
     sb = new StringBuffer();
   }
 }