from typing import Tuple


def _pad_strides(strides: int, axis: int) -> Tuple[int, int, int, int]:
  """Converts int to len 4 strides (`tf.nn.avg_pool` uses length 4)."""
  if axis == 1:
    return (1, 1, strides, strides)
  else:
    return (1, strides, strides, 1)