Optionally specify breed type for procedures

Currently, NetLogo automatically determines the agent type needed for a procedure. There are cases where we want agents of different types to have procedures of the same name but different behavior. For example, in Wolf Sheep Simple 5, we have this code:

It would be nice to be able to optionally do something like:

Being able to (optionally) specify the types of procedures like this could make code easier to understand in many cases, could sometimes make code more concise, and may allow for performance optimizations.