anchor.diff:  // 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.line_printer;
  +library dart_style.src.line_prefix;
   
   import 'chunk.dart';
   import 'nesting.dart';
  
positive.code: 
    /// Creates a new zero-length prefix with initial [indent] whose suffix is
    /// the entire line.
    LinePrefix(int indent)
        : this._(0, {}, indent, new NestingStack());
  
    LinePrefix._(this.length, this.ruleValues, this._indent,
        this._nesting) {
      assert(_nesting != null);
    }
  
    bool operator ==(other) {
      if (other is! LinePrefix) return false;
  
negative.code:           .map((key) => "$key:${ruleValues[key]}")
            .join(" ");
  
        result += " rules $rules";
      }
      return result;
    }
  