code: def remove_kv_store(self, key):
          
          data = {
              'operation': 'DELETE',
              'key': key
          }
          return self.post(self.make_url("/useragent-kv"), data=to_json(data),
                           headers=self.default_headers).text
docs: Remove a key-value store entry.
  
          :param key: string