Convert isX() methods to isX getter.

pkg/analyzer_experimental/lib/src/generated/source.dart

 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 library engine.source;
 import 'java_core.dart';
 import 'sdk.dart' show DartSdk;
 import 'engine.dart' show AnalysisContext;
 /**
  * Instances of the class `SourceFactory` resolve possibly relative URI's against an existing[Source source].
  * @coverage dart.engine.source
  */
@@ skipping 327 matching lines @@
    * Return a hash code for this source.
    * @return a hash code for this source
    * @see Object#hashCode()
    */
   int get hashCode;
 
   /**
    * Return `true` if this source is in one of the system libraries.
    * @return `true` if this is in a system library
    */
-  bool isInSystemLibrary();
+  bool get isInSystemLibrary;
 
   /**
    * Resolve the relative URI against the URI associated with this source object. Return a[Source source] representing the URI to which it was resolved, or `null` if it
    * could not be resolved.
    *
    * Note: This method is not intended for public use, it is only visible out of necessity. It is
    * only intended to be invoked by a [SourceFactory source factory]. Source factories will
    * only invoke this method if the URI is relative, so implementations of this method are not
    * required to, and generally do not, verify the argument. The result of invoking this method with
    * an absolute URI is intentionally left unspecified.
@@ skipping 462 matching lines @@
   void setContents(Source source, String contents) {
     if (contents == null) {
       _contentMap.remove(source);
       _stampMap.remove(source);
     } else {
       _contentMap[source] = contents;
       _stampMap[source] = JavaSystem.currentTimeMillis();
     }
   }
 }