code: function( className ) {
  			var classes = this.attributes[ 'class' ];
  
  			if ( !classes )
  				return;
  
  			// We can safely assume that className won't break regexp.
  			// http://stackoverflow.com/questions/448981/what-characters-are-valid-in-css-class-names
  			classes = CKEDITOR.tools.trim( classes.replace( new RegExp( '(?:\\s+|^)' + className + '(?:\\s+|$)' ), ' ' ) );
  
  			if ( classes )
  				this.attributes[ 'class' ] = classes;
  			else
  				delete this.attributes[ 'class' ];
  		}
docs: Removes a class name from the list of classes.
  
  @since 4.3
  @param {String} className The class name to be removed.