def __init__(self, groups=None):
        super(GroupedRequirements, self).__init__(NamedRequirements)
        self.groups = groups or self.default_groups
        self.filename = None
        self.create_default_groups()
def _model_ready(self, sess):
    """Checks if the model is ready or not.

    Args:
      sess: A `Session`.

    Returns:
      A tuple (is_ready, msg), where is_ready is True if ready and False
      otherwise, and msg is `None` if the model is ready, a `String` with the
      reason why it is not ready otherwise.
    """
    return _ready(self._ready_op, sess, "Model not ready")