 	 * @private
 	###
 
+	# ************************ Private Constant Start *************************
+
 	###*
 	 * These are some static symbolys.
 	 * The state value is designed to be 0, 1, 2. Not by chance.

	 * then these values will be passed to 2 and 3.
	 * @private
	###
	_handlers: []
	$groupNum = 5

	# It only counts when the current promise is on pending state.
	_thenOffset: 0

	$resolveSelf = 'circular promise resolution chain'

	###*
	 * Create cross platform nextTick helper.

	$resolved = 0
	$rejected = 1
	$pending = 2

	###*
	 * This is one of the most tricky part.
