code: function() {
  				if ( list ) {
  
  					// If we have memory from a past run, we should fire after adding
  					if ( memory && !firing ) {
  						firingIndex = list.length - 1;
  						queue.push( memory );
  					}
  
  					( function add( args ) {
  						jQuery.each( args, function( _, arg ) {
  							if ( jQuery.isFunction( arg ) ) {
  								if ( !options.unique || !self.has( arg ) ) {
  									list.push( arg );
  								}
  							} else if ( arg && arg.length && jQuery.type( arg ) !== "string" ) {
  
  								// Inspect recursively
  								add( arg );
  							}
  						} );
  					} )( arguments );
  
  					if ( memory && !firing ) {
  						fire();
  					}
  				}
  				return this;
  			}
docs: Add a callback or a collection of callbacks to the list