Pure hypothesis, since we need to override all methods in the Mock to make them filterable, can't we add to Mock it's own Object + StaticObject logic ?
i.e.
- Mock will simply be a kind of "proxy" to the mocked class/instance.
- an simple `if (isset($this))` allow to differenciate `Mock::applyFilter` from `$mock->applyFilter` call.
- According the ReflectionClass we know if a method is static or not so we can build the correct filter.

This way the Mocker can Mock ***any kind of class*** with a small "footprints" (i.e adding `applyFilter`, `_filter` and `$_methodFilters` to the attributes/methods).

Does that make sense ?