small method to empty values if resource is removed or absent

		Args:
			None

		Return:
			None: empties selected resource attributes

def _empty_resource_attributes(self):

		'''
		small method to empty values if resource is removed or absent

		Args:
			None

		Return:
			None: empties selected resource attributes
		'''

		self.status_code = 404
		self.headers = {}
		self.exists = False

		# build RDF
		self.rdf = self._build_rdf()

		# if NonRDF, empty binary data
		if type(self) == NonRDFSource:
			self.binary.empty()