Without this, setting an item to None that did not already exist failed, because the kv delete operation did not find the referenced key. This also checks that the index is not 0, which is not allowed as the working set is 1-indexed.
Without this, setting an item to None that did not already exist failed, because the kv delete operation did not find the referenced key. This also checks that the index is not 0, which is not allowed as the working set is 1-indexed.