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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 _add_argument_register(self, reg_offset):
 """ Registers a register offset as being used as an argument to the function. :param reg_offset: The offset of the register to register. """

        if reg_offset in self._function_manager._arg_registers and \
                    reg_offset not in self._argument_registers:
            self._argument_registers.append(reg_offset)