def METHOD_NAME(self):
    """Return reference unitaries for test circuits"""
    # Gate matrices
    gate_h = np.array([[1, 1], [1, -1]]) / np.sqrt(2)
    gate_x = np.array([[0, 1], [1, 0]])
    gate_y = np.array([[0, -1j], [1j, 0]])
    gate_z = np.array([[1, 0], [0, -1]])
    gate_cx = np.array([[1, 0, 0, 0], [0, 0, 0, 1], [0.0, 0, 1, 0], [0, 1, 0, 0]])
    # Unitary matrices
    target_unitary1 = np.kron(np.kron(gate_h, gate_h), gate_h)
    target_unitary2 = np.kron(np.eye(2), gate_cx)
    target_unitary3 = np.kron(gate_cx, gate_y)
    target_unitary4 = np.dot(
        np.kron(gate_cx, np.eye(2)),
        np.dot(np.kron(np.eye(2), gate_cx), np.kron(np.eye(4), gate_h)),
    )
    target_unitary5 = np.kron(
        np.kron(np.dot(gate_x, gate_z), np.dot(gate_z, gate_y)), np.dot(gate_y, gate_x)
    )
    return [target_unitary1, target_unitary2, target_unitary3, target_unitary4, target_unitary5]