def test_fib_generator():
    """Tests fib generator output """

    for index, number in fibonacci_generator():
        #: since the generator is infinite, we'd like to terminate at some
        #: point
        if index >= len(FIBONACCI_NUMBERS):
            break
        assert number == FIBONACCI_NUMBERS[index]
def problem_2():
    """ Attempt to solve the problem... """

    total = 0
    for value in fibonacci_generator():
        if value[1] >= 4000000:
            break
        if value[1] % 2 == 0:
            total += value[1]
    return total