code: function( editor ) {
  			if ( this._.feature )
  				return this._.feature;
  
  			var feature = this;
  
  			// If button isn't a feature, return command if is bound.
  			if ( !this.allowedContent && !this.requiredContent && this.command )
  				feature = editor.getCommand( this.command ) || feature;
  
  			return this._.feature = feature;
  		}
docs: Returns this button's {@link CKEDITOR.feature} instance.
  
  It may be this button instance if it has at least one of
  `allowedContent` and `requiredContent` properties. Otherwise,
  if a command is bound to this button by the `command` property, then
  that command will be returned.
  
  This method implements the {@link CKEDITOR.feature#toFeature} interface method.
  
  @since 4.1
  @param {CKEDITOR.editor} Editor instance.
  @returns {CKEDITOR.feature} The feature.