docs: function( editor ) {
  			if ( editor.blockless )
  				return;
  
  			editor.addCommand( pluginName, horizontalruleCmd );
  			editor.ui.addButton && editor.ui.addButton( 'HorizontalRule', {
  				label: editor.lang.horizontalrule.toolbar,
  				command: pluginName,
  				toolbar: 'insert,40'
  			} );
  		}