def _qpos_tag(qubits: cirq.Qid | tuple[cirq.Qid]):
    """Given a qubit or qubits, return a "position tag" (used for drawing).

    For multiple qubits, the tag is for the first qubit.
    """
    if isinstance(qubits, cirq.Qid):
        return _qpos_tag((qubits,))
    x = min(qubits)
    return f'q{x}'
Given a qubit or qubits, return a "position tag" (used for drawing).

    For multiple qubits, the tag is for the first qubit.
    
cirq-core/cirq/contrib/quimb/density_matrix.py