def test_find_unused_qubits_pauli_op(self):
"""
Tests that unused qubits are found correctly.
"""
operator = I ^ I ^ I ^ Z ^ I
unused = _find_unused_qubits(operator)
expected = [0, 2, 3, 4]
self.assertEqual(unused, expected)
def test_find_unused_qubits_3(self):
"""
Tests that unused qubits are found correctly.
"""
operator = (Z ^ I ^ Z) + (I ^ Z ^ I)
unused = _find_unused_qubits(operator)
expected = []
self.assertEqual(unused, expected)
