<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def augment_items(cls, items, **defaults):
 		""" 		Iterate over the items, keeping a adding properties as supplied by 		Sentinel objects encountered. 		a 		b 		c 		[False, False, True] 		a 		b 		c 		True 		[False, True, True] 		#default 		#default 		#foo 		"""

		properties = defaults
		for item in items:
			# allow the Sentinel to be just the class itself, which is to be
			#  constructed with no parameters.
			if isinstance(item, type) and issubclass(item, Sentinel):
				item = item()
			if isinstance(item, Sentinel):
				properties.update(item.properties)
				continue
			yield AugmentableMessage(item, **properties)