Add the specified key / data pair to this list, and load into the specified result a reference to the pair in the list. Search for the correct position for key from the back of the list (in descending order by key value). The result reference must be released (using releaseReferenceRaw) when it is no longer needed. Load into the optionally specified newFrontFlag a true value if the pair is at the front of the list, and a false value otherwise. Return 0 on success, and a non-zero value (with no effect on the list) if key is already in the list.