Constructs the inout_threads from the items according to the flags and then changes the content of
the this to contain only references to messages which satisfy the kind.
When there are no items or the kind is camel_match_threads_kind_none, the
function does nothing.
| this | |
| items |
all items used for thread creation |
| kind |
one of MatchThreadsKind |
| flags |
a bit-or of FolderThreadFlags |
| cancellable |
a Cancellable, or |