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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 __execute_stm(self, instr):
 """Execute STM instruction. """

        assert instr.operands[0].size in [8, 16, 32, 64, 128, 256]
        assert instr.operands[2].size == self.__mem.address_size

        op0_val = self.read_operand(instr.operands[0])  # Data.
        op2_val = self.read_operand(instr.operands[2])  # Memory address.

        op0_size = instr.operands[0].size

        self.write_memory(op2_val, op0_size // 8, op0_val)

        return None