Creating type evaluation annotation

[Marek Mosiewicz]

I'm Java developer,but had some experience with Python based
ERP software. It is quite serious application and I feel 
unconfortable with not having type checking. I do not say language
should be static, but having checking method signature
is big win. For example in refactoring.
I know that Python 3 has possibility to have indicate
type for varibale or param
What could be great to have possibility to annotate any 
class with what I call "type evaluator" function.
That could check method signature with rules specific 
for given type.
The simplest evaluator would simply check if signature
is same as method definition. 
But it could go futher. It could check whatever is valid 
logic for creating methods in given class and whatever 
are valid params for given method.
Even more powerful evaluator could be not only
valid/not valid indicator. It could validate
and suggest next param or method part name for given
written part of call. That could make python IDEs
much more powerful
>From my experience having signature checking and
hinting params when writing code is really big win.
I could simply refactor 100000 lines of code in
Java, but same for Python is much more difficult

Best regards,
    Marek Mosiewicz