qiskit/transpiler/passes/mapping/lookahead_swap.py
def _copy_circuit_metadata(source_dag, coupling_map):
    """Return a copy of source_dag with metadata but empty.
    Generate only a single qreg in the output DAG, matching the size of the
    coupling_map."""

    target_dag = DAGCircuit()
    target_dag.name = source_dag.name

    for creg in source_dag.cregs.values():
        target_dag.add_creg(creg)

    device_qreg = QuantumRegister(len(coupling_map.physical_qubits), 'q')
    target_dag.add_qreg(device_qreg)

    return target_dag
def _copy_circuit_metadata(source_dag, coupling_map):
    """Return a copy of source_dag with metadata but empty.
    Generate only a single qreg in the output DAG, matching the size of the
    coupling_map."""

    target_dag = DAGCircuit()
    target_dag.name = source_dag.name

    for creg in source_dag.cregs.values():
        target_dag.add_creg(creg)

    device_qreg = QuantumRegister(len(coupling_map.physical_qubits), 'q')
    target_dag.add_qreg(device_qreg)

    return target_dag
Return a copy of source_dag with metadata but empty.
    Generate only a single qreg in the output DAG, matching the size of the
    coupling_map.