import tensorflow as tf

      Operation.
    """
    with tf.name_scope('environment/simulate'):
      if action.dtype in (tf.float16, tf.float32, tf.float64):
        action = tf.check_numerics(action, 'action')
      observ_dtype = self._parse_dtype(self._batch_env.observation_space)
      observ, reward, done = tf.py_func(
          lambda a: self._batch_env.step(a)[:3], [action],
