The following test cases failed:
Function being tested: hours_difference
Case: time_1_slightly_smaller_than_time_2
Cause: IncorrectReturnValue:
What happens when time_1 is slightly smaller than time_2?
Function being tested: hours_difference
Case: time_1_slightly_larger_than_time_2
Cause: IncorrectReturnValue:
What happens when time_1 is slightly larger than time_2?
Function being tested: hours_difference
Case: time_1_much_smaller_than_time_2
Cause: IncorrectReturnValue:
What happens when time_1 is much smaller than time_2?
Function being tested: hours_difference
Case: time_1_much_larger_than_time_2
Cause: IncorrectReturnValue:
What happens when time_1 is much larger than time_2?

    Summary of results:
    41 tests run
    37 tests passed
    4 tests produced incorrect output
    0 tests timed out