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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 listcall(self, *arg, **kw):
 """Call each plugin sequentially. Return the first result that is not None. """

        final_result = None
        for _, meth in self.plugins:
            result = meth(*arg, **kw)
            if final_result is None and result is not None:
                final_result = result
        return final_result