docs: def has_commit(self, client_key=None):
          """
          Return True if client has new commit.
  
          :param client_key: The client key
          :type client_key: str
          :return:
          :rtype: boolean
          """
          if client_key is None and self.current_client is None:
              raise ClientNotExist()
  
          if client_key:
              if not self.clients.has_client(client_key):
                  raise ClientNotExist()
  
              client = self.clients.get_client(client_key)
  
              return client.has_commit()
  
          if self.current_client:
              client = self.current_client
  
              return client.has_commit()
  
          return False