def _circuit_diagram_info_(self, _args: cirq.CircuitDiagramInfoArgs) -> cirq.CircuitDiagramInfo:
        """Returns the information required to draw out the circuit diagram for this channel."""
        symbols = (
            [self._name]
            if self._num_qubits == 1
            else [f'{self._name}[{i+1}]' for i in range(self._num_qubits)]
        )
        return protocols.CircuitDiagramInfo(wire_symbols=symbols)
Returns the information required to draw out the circuit diagram for this channel.
cirq-core/cirq/ops/state_preparation_channel.py