=Investigation II=

: In the previous investigation, the functions that were defined for manipulating our time object are not tied directly to our time object. Given our time object alone, we won't be able to tell that there exist a function called sum_times() which can be used to add two time objects and return their sum.

== Part 1 - Classes and Methods for our Time objects ==

: The following illustration shows how we can change external functions to become object methods (aka class functions) for our Time object. It is simply by moving the function definitions to be under the class definition for the Time object: <source lang="python">