def METHOD_NAME(self, label="statevector", pershot=False, conditional=False):
    """Save the current simulator quantum state as a statevector.
    Args:
        pershot (bool): if True save a list of statevectors for each
                        shot of the simulation [Default: False].
        label (str): the key for retrieving saved data from results.
        conditional (bool): if True save pershot data conditional on the
                            current classical register values
                            [Default: False].
    Returns:
        QuantumCircuit: with attached instruction.
    .. note::
        This instruction is always defined across all qubits in a circuit.
    """
    qubits = default_qubits(self)
    instr = SaveStatevector(len(qubits), label=label, pershot=pershot, conditional=conditional)
    return self.append(instr, qubits)