code: def as_json(self,
                  entity_url,
                  context=None):
          
          try:
              urllib.request.urlopen(entity_url)
          except urllib.error.HTTPError:
              raise ValueError("Cannot open {}".format(entity_url))
          entity_graph = self.read(entity_url)
          entity_json = json.loads(
              entity_graph.serialize(
                  format='json-ld',
                  context=context).decode())
          return json.dumps(entity_json)
docs: Method takes a entity uri and attempts to return the Fedora Object
          as a JSON-LD.
  
          Args:
              entity_url(str): Fedora Commons URL of Entity
              context(None): Returns JSON-LD with Context, default is None
  
          Returns:
              str: JSON-LD of Fedora Object