 	$groupNum = 5
 
 	$circularErrorInfo = 'circular promise resolution chain'
+
+	$tryErr = {}
 
 	# ************************* Private Constant End **************************
 


		return

	###*
	 * Decide how handlers works.
	 * @private

	resolveValue = (x, resolve, reject) ->
		type = typeof x
		if x != null and (type == 'function' or type == 'object')
			xthen = getXthen x, reject
			return if xthen == $tryErr

			if typeof xthen == 'function'
				resolveXthen x, xthen, resolve, reject
			else
				resolve x
		else
