Convert isX() methods to isX getter.

pkg/analyzer_experimental/lib/src/generated/source_io.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.io;
 import 'source.dart';
 import 'dart:io';
 import 'java_core.dart';
 import 'java_io.dart';
 import 'sdk.dart' show DartSdk;
 import 'engine.dart' show AnalysisContext, AnalysisEngine;
 export 'source.dart';
@@ skipping 69 matching lines @@
   int get modificationStamp {
     int stamp = _contentCache.getModificationStamp(this);
     if (stamp != null) {
       return stamp;
     }
     return _file.lastModified();
   }
   String get shortName => _file.getName();
   UriKind get uriKind => _uriKind;
   int get hashCode => _file.hashCode;
-  bool isInSystemLibrary() => identical(_uriKind, UriKind.DART_URI);
+  bool get isInSystemLibrary => identical(_uriKind, UriKind.DART_URI);
   Source resolveRelative(Uri containedUri) {
     try {
       Uri resolvedUri = file.toURI().resolveUri(containedUri);
       return new FileBasedSource.con2(_contentCache, new JavaFile.fromUri(resolvedUri), _uriKind);
     } catch (exception) {
     }
     return null;
   }
   String toString() {
     if (_file == null) {
@@ skipping 217 matching lines @@
     }
     return null;
   }
   Source resolveAbsolute(ContentCache contentCache, Uri uri) {
     if (!isFileUri(uri)) {
       return null;
     }
     return new FileBasedSource.con1(contentCache, new JavaFile.fromUri(uri));
   }
 }