def METHOD_NAME(self, params, label="amplitudes", pershot=False, conditional=False):
    """Save complex statevector amplitudes.
    Args:
        params (List[int] or List[str]): the basis states to return amplitudes for.
        label (str): the key for retrieving saved data from results.
        pershot (bool): if True save a list of amplitudes vectors for each
                        shot of the simulation rather than the a single
                        amplitude vector [Default: False].
        conditional (bool): if True save the amplitudes vector conditional
                            on the current classical register values
                            [Default: False].
    Returns:
        QuantumCircuit: with attached instruction.
    Raises:
        ExtensionError: if params is invalid for the specified number of qubits.
    """
    qubits = default_qubits(self)
    instr = SaveAmplitudes(
        len(qubits), params, label=label, pershot=pershot, conditional=conditional
    )
    return self.append(instr, qubits)