feat: set arg expectations on methods

[crookse]

Summary

What:

Test double methods that can set up to return values should have arg expectations defined as well.

Why:

It's common to set up a method like "expect this method to take in this arg and return this value"

Acceptance Criteria

Below is a list of tasks that must be completed before this issue can be closed.

• Write documentation
• Write unit tests
• Write integration tests

Example Pseudo Code (for implementation)

fake.method("blah").withArgs("hello").willReturn("world");