def _need_merge_pulled_through(op_at_q: ops.Operation, is_at_last_busy_moment: bool) -> bool:
    """With a pulling through pauli gate before op_at_q, need to merge with the
    pauli in the conditions below."""
    # The op must be mergable and single-qubit
    if not (_is_single_qubit_operation(op_at_q) and has_unitary(op_at_q)):
        return False
    # Either non-Clifford or at the last busy moment
    return is_at_last_busy_moment or not _is_clifford_op(op_at_q)
With a pulling through pauli gate before op_at_q, need to merge with the
    pauli in the conditions below.
cirq-core/cirq/transformers/dynamical_decoupling.py