code: def exists(self, uri):
          
          ##entity_uri = "/".join([self.base_url, entity_id])
          try:
              urllib.request.urlopen(uri)
              return True
          except urllib.error.HTTPError:
              return False
docs: Method returns true is the entity exists in the Repository,
          false, otherwise
  
          Args:
              uri(str): Entity URI
  
          Returns:
              bool