anchor.diff:    final List<Expression> args;
   
     MethodCall(this.reference, this.args);
  +  MethodCall.withNoArguments(this.reference) : args = [];
   
     @override
     String toString() => "MethodCall(reference: ${reference}, args: ${args})";
  
positive.code: 
    ClassBlock(this.name, this.args, this.extension, this.block);
  
  
  }
  
  class TryCatchStatement extends Statement {
  
negative.code:   final Expression expression;
  
    ExpressionStatement(this.expression);
    
    factory ExpressionStatement.forMethodCall(dynamic ref, [List<Expression> args = const []]) {
      return new ExpressionStatement(new MethodCall(ref, args));
    }
  }
  
  class MethodCall extends Expression {
  