Return the class name for the current frame.
    If the result is ** None ** means that the call is made from a module.

def check_class():
    """
    Return the class name for the current frame.
    If the result is ** None ** means that the call is made from a module.
    """
    # get frames
    frames = inspect.stack()
    cls = None
    # should be the third frame
    # 0: this function
    # 1: function/decorator
    # 2: class that contains the function
    if len(frames) > 2:
        frame = frames[2][0]
        if '__module__' in frame.f_code.co_names:
            cls = SillyClass(**frame.f_locals)
            cls.__cls_name__ = frame.f_code.co_name
    return cls