Support generic methods. Fix #556.

lib/src/argument_list_visitor.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart_style.src.argument_list_visitor;
 
 import 'dart:math' as math;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 135 matching lines @@
       this._arguments,
       this._functions,
       this._argumentsAfterFunctions);
 
   /// Builds chunks for the argument list.
   void visit() {
     // If there is just one positional argument, it tends to look weird to
     // split before it, so try not to.
     if (_isSingle) _visitor.builder.startSpan();
 
-    // Nest around the parentheses in case there are comments before or after
-    // them.
-    _visitor.builder.nestExpression();
     _visitor.builder.startSpan();
     _visitor.token(_leftParenthesis);
 
     _arguments.visit(_visitor);
 
     _visitor.builder.endSpan();
 
     if (_functions != null) {
       // TODO(rnystrom): It might look better to treat the parameter list of the
       // first function as if it were an argument in the preceding argument list
@@ skipping 17 matching lines @@
         }
       }
 
       _visitor.builder.startSpan();
       _argumentsAfterFunctions.visit(_visitor);
       _visitor.builder.endSpan();
     }
 
     _visitor.token(_rightParenthesis);
 
-    _visitor.builder.unnest();
-
     if (_isSingle) _visitor.builder.endSpan();
   }
 
   /// Returns `true` if [expression] is a [FunctionExpression] with a non-empty
   /// block body.
   static bool _isBlockFunction(Expression expression) {
     if (expression is NamedExpression) {
       expression = (expression as NamedExpression).expression;
     }
 
@@ skipping 255 matching lines @@
 
     // TODO(rnystrom): Should we step into parenthesized expressions?
 
     if (expression is ListLiteral) return expression.leftBracket;
     if (expression is MapLiteral) return expression.leftBracket;
 
     // Not a collection literal.
     return null;
   }
 }