def get_op_slice_sizes(op_slices):
  """Returns OpSlice sizes for a list of list of OpSlice.

  The outer list has an element per op, while the inner list is the list of
  OpSlice that compose the op.

  Args:
    op_slices: List of list of OpSlice.

  Returns:
    List of list of OpSlice sizes where the outer list has an entry per op.
  """
  op_slice_sizes = []
  for op in op_slices:
    op_slice_sizes.append([op_slice.slice.size for op_slice in op])

  return op_slice_sizes