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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 instruction_addresses(self):
 """ Addresses of instructions in this block. """

        if self._instruction_addresses is None:
            if self.statements is None:
                self._instruction_addresses = [ ]
            else:
                self._instruction_addresses = [ (s.addr + s.delta) for s in self.statements if type(s) is stmt.IMark ]
        return self._instruction_addresses