Implement a clock that handles times without dates.
You should be able to add and subtract minutes to it.
Two clocks that represent the same time should be equal to each other.
You will also need to implement
.to_string() for the
We will be using this to display the Clock's state.
You can either do it via implementing it directly or using the Display trait.
If so, try implementing the Display trait for
Traits allow for a common way to implement functionality for various types.
For additional learning, consider how you might implement
String::from for the
You don't have to actually implement this—it's redundant with
Display, which is generally the
better choice when the destination type is
String—but it's useful to have a few type-conversion
traits in your toolkit.