reference :
https://npmjs.org/package/JQDeferred
	
	
	
		
			
			https://npmjs.org/package/JQDeferred
		JavaScript:
	
	function getBIDS(NodeKey) {
	var def = Deferred();
	var read2DB = new Firebase("https://" + baseURL + "/BIDS");
	read2DB.child(NodeKey).once('value', function(snap) {
		def.resolve(snap);
	});
	return def.promise();
}
//callback
getBIDS("-JDQ0Ba4ZfC1CJxHduNZ").done(function(e){
	console.log(e.val().debugfield);
});