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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 ltrim(self, key, start, stop):
 """Trim an existing list so that it will contain only the specified range of elements specified. :raises TypeError: if start or stop is not int """

        if not isinstance(start, int):
            raise TypeError("start argument must be int")
        if not isinstance(stop, int):
            raise TypeError("stop argument must be int")
        fut = self.execute(b'LTRIM', key, start, stop)
        return wait_ok(fut)