def _calc_pulled_through(
    moment: circuits.Moment, input_pauli_ops: ops.PauliString
) -> ops.PauliString:
    """Calculates the pulled_through such that circuit(input_pauli_ops, moment.clifford_ops) is
    equivalent to circuit(moment.clifford_ops, pulled_through).
    """
    clifford_ops_in_moment: list[ops.Operation] = [
        op for op in moment.operations if _is_clifford_op(op)
    ]
    return input_pauli_ops.after(clifford_ops_in_moment)
Calculates the pulled_through such that circuit(input_pauli_ops, moment.clifford_ops) is
    equivalent to circuit(moment.clifford_ops, pulled_through).
    
cirq-core/cirq/transformers/dynamical_decoupling.py