anchor.diff:    String secondaryText;
   
     /// An optional icon name to replace the expand arrows with a custom icon.
  -  ///
  +  @Input()
  +  set expandIcon(String expandIcon) => _expandIcon = expandIcon;
  +
  +  String _expandIcon;
  +
     /// If a custom icon is used, then the icon disappears when the panel is
  -  /// expanded. By default, the expand icon is "expand_less."
  -  String _expandIcon;
  +  /// expanded.
  +  ///
  +  /// By default, the expand icon is "expand_less."
     String get expandIcon => _expandIcon ?? _defaultExpandIcon;
  -
  -  @Input()
  -  set expandIcon(String expandIcon) => _expandIcon = expandIcon;
   
     /// If true, the expand icon should always be visible regardless whether a
     /// custom icon is used.
  
positive.code:   @Input()
    bool cancelDisplayed = true;
  
    @Input()
    bool enterAccepts = false;
  
  
negative.code: /// takes into account the state of the other panels in the set, and issues the
  /// appropriate actions onto each individual panel.
  ///
  /// __Attributes:__
  ///
  ///  - `wide` -- When specified the width of the panel when expanded, is
  ///    slightly wider then its width when collapsed.
  ///  - `flat` -- Indicates that the panel should not "float" or separate from
  ///    other panels when expanded.
  ///
  @Component(
    selector: 'material-expansionpanel',
  