docs: def from_client(cls, client):
          """
          Constructs a configuration object from an existing client instance. If the client has already been created with
          a configuration object, returns that instance.
  
          :param client: Client object to derive the configuration from.
          :type client: docker.client.Client
          :return: ClientConfiguration
          """
          if hasattr(client, 'client_configuration'):
              return client.client_configuration
          kwargs = {'client': client}
          for attr in cls.init_kwargs:
              if hasattr(client, attr):
                  kwargs[attr] = getattr(client, attr)
          if hasattr(client, 'api_version'):
              kwargs['version'] = client.api_version
          return cls(**kwargs)