code: def update(self, sparql_query_only=False, auto_refresh=None, update_binary=True):
  		'''
  		Method to update resources in repository.  Firing this method computes the difference in the local modified graph and the original one,
  		creates an instance of SparqlUpdate and builds a sparql query that represents these differences, and sends this as a PATCH request.
  		Note: send PATCH request, regardless of RDF or NonRDF, to [uri]/fcr:metadata
  		If the resource is NonRDF (Binary), this also method also updates the binary data.
  		Args:
  			sparql_query_only (bool): If True, returns only the sparql query string and does not perform any actual updates
  			auto_refresh (bool): If True, refreshes resource after update. If left None, defaults to repo.default_auto_refresh
  			update_binary (bool): If True, and resource is NonRDF, updates binary data as well
  		Returns:
  			(bool)
  		'''
  		self._diff_graph()
  		sq = SparqlUpdate(self.rdf.prefixes, self.rdf.diffs)
  		if sparql_query_only:
  			return sq.build_query()
  		response = self.repo.api.http_request(
  			'PATCH',
  			'%s/fcr:metadata' % self.uri,
  			data=sq.build_query(),
  			headers={'Content-Type':'application/sparql-update'})
  		if response.status_code != 204:
  			logger.debug(response.content)
  			raise Exception('HTTP %s, expecting 204' % response.status_code)
  		if type(self) == NonRDFSource and update_binary and type(self.binary.data) != requests.models.Response:
  			self.binary._prep_binary()
  			binary_data = self.binary.data
  			binary_response = self.repo.api.http_request(
  				'PUT',
  				self.uri,
  				data=binary_data,
  				headers={'Content-Type':self.binary.mimetype})
  			if not auto_refresh and not self.repo.default_auto_refresh:
  				logger.debug("not refreshing resource RDF, but updated binary, so must refresh binary data")
  				updated_self = self.repo.get_resource(self.uri)
  				self.binary.refresh(updated_self)
  		if hasattr(self,'_post_update'):
  			self._post_update()
  		'''
  		If not updating binary, pass that bool to refresh as refresh_binary flag to avoid touching binary data
  		'''
  		if auto_refresh:
  			self.refresh(refresh_binary=update_binary)
  		elif auto_refresh == None:
  			if self.repo.default_auto_refresh:
  				self.refresh(refresh_binary=update_binary)
  		return True