def test_previous_instruction_in_scope_failures(self):
"""Test the failure paths of the peek and pop methods for retrieving the most recent
instruction in a scope."""
test = QuantumCircuit(1, 1)
with self.assertRaisesRegex(CircuitError, r"This circuit contains no instructions\."):
test._peek_previous_instruction_in_scope()
with self.assertRaisesRegex(CircuitError, r"This circuit contains no instructions\."):
test._pop_previous_instruction_in_scope()
with test.for_loop(range(2)):
with self.assertRaisesRegex(CircuitError, r"This scope contains no instructions\."):
test._peek_previous_instruction_in_scope()
with self.assertRaisesRegex(CircuitError, r"This scope contains no instructions\."):
test._pop_previous_instruction_in_scope()
