code: function preloadStylesSet( editor ) {
  		editor.getStylesSet( function( styles ) {
  			// Wait for editor#loaded, so plugins could add their listeners.
  			// But listen with high priority to fire editor#stylesSet before editor#uiReady and editor#setData.
  			editor.once( 'loaded', function() {
  				// Note: we can't use fireOnce because this event may canceled and fired again.
  				editor.fire( 'stylesSet', { styles: styles } );
  			}, null, null, 1 );
  
  			loadPlugins( editor );
  		} );
  	}
docs: Preloads styles set file (config.stylesSet). If stylesSet was defined directly (by an array) this function will call loadPlugins fully synchronously. If stylesSet is a string (path) loadPlugins will be called asynchronously. In both cases - styles will be preload before plugins initialization.