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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 load(self, addr, length=1):
 """ Load one or more addresses. :param addr: byte address of load location :param length: All address from addr until addr+length (exclusive) are loaded (default: 1) """

        if addr is None:
            return
        elif not isinstance(addr, Iterable):
            self.first_level.load(addr, length=length)
        else:
            self.first_level.iterload(addr, length=length)