This function exists to determine if the process or window that previously wrote to a chain is still around.
If not, then it's safe to append to that chain (to reduce the number of chain starts). If the creator of a
chain is still active, then you can't assume that the chain is free for reuse.
This function exists to determine if the process or window that previously wrote to a chain is still around. If not, then it's safe to append to that chain (to reduce the number of chain starts). If the creator of a chain is still active, then you can't assume that the chain is free for reuse.