docs: def parse_uri(self, uri=None):
  
  		'''
  		parses and cleans up possible uri inputs, return instance of rdflib.term.URIRef
  
  		Args:
  			uri (rdflib.term.URIRef,str): input URI
  
  		Returns:
  			rdflib.term.URIRef
  		'''
  
  		# no uri provided, assume root
  		if not uri:
  			return rdflib.term.URIRef(self.root)
  
  		# string uri provided
  		elif type(uri) == str:
  
  			# assume "short" uri, expand with repo root
  			if type(uri) == str and not uri.startswith('http'):
  				return rdflib.term.URIRef("%s%s" % (self.root, uri))
  
  			# else, assume full uri
  			else:
  				return rdflib.term.URIRef(uri)
  
  		# already rdflib.term.URIRef
  		elif type(uri) == rdflib.term.URIRef:
  			return uri
  
  		# unknown input
  		else:
  			raise TypeError('invalid URI input')