import json


def assert_cassette_empty(cass):
    assert len(cass) == 0
    assert cass.play_count == 0


def assert_cassette_has_one_response(cass):
    assert len(cass) == 1
    assert cass.play_count == 1


def assert_is_json_bytes(b: bytes):
    assert isinstance(b, bytes)
    try:
        json.loads(b.decode("utf-8"))
    except Exception:
        assert False
    assert True