import tensorflow as tf

  A tensor.
  """
  if alpha != 0.:
    negative_part = tf.nn.relu(-x)
  x = tf.nn.relu(x)
  if max_value is not None:
    max_value = _to_tensor(max_value, x.dtype.base_dtype)
    zero = _to_tensor(0., x.dtype.base_dtype)
