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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 reset(self):
 """Reset internal state. """

        self._solver.reset()

        # Memory versioning.
        self._mem_instance = 0

        self._mem_init = smtsymbol.BitVecArray(self._address_size, 8, "MEM_{}".format(self._mem_instance))
        self._mem_curr = self.make_array(self._address_size, "MEM_{}".format(self._mem_instance))

        self._var_name_mappers = {}