def get_op_slices(ops, op_reg_manager):
  """Returns list of OpSlice per op in a list of ops.

  Args:
    ops: List of tf.Operation.
    op_reg_manager: OpRegularizerManager that tracks the slicing.

  Returns:
    List of list of OpSlice, where the outer list has a list per op, and the
    inner list is a list of OpSlice that compose the op.
  """
  op_slices = []
  for op in ops:
    op_slices.append(op_reg_manager.get_op_slices(op))
  return list(filter(None, op_slices))