`AerStatevector(QuantumVolume(1))` raises an error

[hhorii]

Informations

• Qiskit Aer version: 0.11.1
• Python version: 3.8
• Operating system: MacOS

What is the current behavior?

AerStatevector(QuantumVolume(1)) raises an error.
This is because QuantumVolume(1).data[0].operation.definition returns an empty QuantumCircuit, which return True with not operation.

Steps to reproduce the problem

from qiskit.circuit.library import QuantumVolume
from qiskit_aer.quantum_info.states import AerStatevector
state = AerStatevector(QuantumVolume(1))

What is the expected behavior?

No error.

Suggested solutions

qiskit-aer/qiskit_aer/quantum_info/states/aer_statevector.py

Line 207 in d13c2a5

if not definition:

This test expression should check == None.

This issue is reported by @derwind

[hhorii]

#1643 resolved this.