How to use the rpcq.messages.ParameterAref function in rpcq

:param expression: an Expression
        """
        if isinstance(expression, BinaryExp):
            left = self._resolve_memory_references(expression.op1)
            right = self._resolve_memory_references(expression.op2)
            return expression.fn(left, right)
        elif isinstance(expression, Function):
            return expression.fn(self._resolve_memory_references(expression.expression))
        elif isinstance(expression, Parameter):
            raise ValueError(f"Unexpected Parameter in gate expression: {expression}")
        elif isinstance(expression, float) or isinstance(expression, int):
            return expression
        elif isinstance(expression, MemoryReference):
            return self._variables_shim.get(
                ParameterAref(name=expression.name, index=expression.offset), 0
            )
        else:
            raise ValueError(f"Unexpected expression in gate parameter: {expression}")

def write_memory(self, *, region_name: str, offset: int = 0, value=None):
        """
        Writes a value into a memory region on the QAM at a specified offset.

        :param region_name: Name of the declared memory region on the QAM.
        :param offset: Integer offset into the memory region to write to.
        :param value: Value to store at the indicated location.
        """
        assert self.status in ["loaded", "done"]

        aref = ParameterAref(name=region_name, index=offset)
        self._variables_shim[aref] = value

        return self