anchor.diff:  import 'package:angular/core/parser/parser.dart';
   import 'package:angular/utils.dart' show isReservedWord;
  -import 'dart:math';
   
   class DartGetterSetterGen extends ParserBackend {
  -  final Set<String> properties = new Set<String>();
  -  final Set<String> calls = new Set<String>();
  -  final Set<String> symbols = new Set<String>();
  +  final properties = new Set<String>();
  +  final calls = new Set<String>();
  +  final symbols = new Set<String>();
   
     bool isAssignable(expression) => true;
   
  
positive.code:     });
  
      DartGetterSetterGen backend = this.backend;
      sink.write(generateClosureMap(backend.properties, backend.calls, backend.symbols));
    }
  
    generateClosureMap(Set<String> properties,
  
negative.code:     return '{\n${lines.join(",\n")}\n  }';
    }
  
    generateSymbolMap(Set<String> symbols) {
      var lines = symbols.map((key) => '    r"${key}": #$key');
      return '{\n${lines.join(",\n")}\n  }';
    }
  