Can I find the class of a method in a decorator.

[Antoon Pardon]

Using python 3.4/3.5

Suppose I have the following class:

class Tryout:

    @extern
    def method(self, ...)

Now how can I have access to the Tryout class in
the extern function when it is called with method
as argument

def extern(f):
    the_class = ????

f.__class doesn't work, if I write the following

def extern(f)
    print(f.__class__)

the result is: <class 'function'>, so that doesn't work.
Looking around I didn't find an other obvious candidate
to try. Anybody an idea?

-- 
Antoon Pardon