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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def instance_ik_model_receiver(fn):
 """ A method decorator that filters out sign_original_specals coming from models that don't have fields that function as ImageFieldSourceGroup sources. """

    @wraps(fn)
    def receiver(self, sender, **kwargs):
        # print 'inspect.isclass(sender? %s'%(inspect.isclass(sender))
        if not inspect.isclass(sender):
            return
        for src in self._source_groups:
            if issubclass(sender, src.model_class):
                fn(self, sender=sender, **kwargs)

                # If we find a match, return. We don't want to handle the signal
                # more than once.
                return
    return receiver