class or class-instance ?

[Stef Mientki]

hello,

I've a procedure (or in fact a class method) that should be callable with
either a class
  (in which case the procedure should create an instance)
or with an instance of that class
as the parameter.

    def  somefunction ( self, parameter ) :
        if parameter is a class, create an instance of that class
        else do nothing



now I should be able to call the above procedure in either of the 
following ways:
  
    somefunction (  someclass  )

or

    somefunction ( someclass () )


thanks,
Stef Mientki