 	###
 	assertIterable = (obj) ->
 		return if obj instanceof Array
-		throw genTypeError $invalid_argument
+		throw genTypeError 'invalid_argument'
 
 	###*
 	 * Generate type error object.

	settleWithX = (p, x) ->
		# 2.3.1
		if x == p and x
			settlePromise p, $rejected, genTypeError($circularChain)
			return

		# 2.3.2

	$resolved = 1
	$pending = 2

	$promiseTrace = '_pt'
	$settlerTrace = '_st'

	$fromPrevious = 'From previous event:'

