force LABjs to pause in execution at this point in the chain, until the execution thus far finishes, before proceeding
function(){
					if (arguments.length > 0) {
						for (var i=0; i<arguments.length; i++) {
							chain.push(arguments[i]);
						}
						group = chain[chain.length-1];
					}
					else group = false;

					advance_exec_cursor();

					return chainedAPI;
				}