UNREF every pointer at the end of the function .
在函数的结束处UNREF第一个指针。
When using REF and UNREF , you need to obey these rules for pointer assignments
当使用REF和UNREF时，您需要遵守这些指针的分配规则
REF and UNREF might be more complicated , depending on what you wanted to do .
REF和UNREF可能会更复杂，这取决于您想要做的事情。
unref