* a key that appears once in `right` might appear multiple times in `left`). We don't
         * guarantee behavior in that case, anyway, and the current behavior is likely undesirable.
         * So that's either a reason to feel free to change it or a reason to not bother thinking
         * further about this.
         */
        V rightValue = uncheckedCastNullableTToT(onlyOnRight.remove(leftKey));

         * a key that appears once in `right` might appear multiple times in `left`). We don't
         * guarantee behavior in that case, anyway, and the current behavior is likely undesirable.
         * So that's either a reason to feel free to change it or a reason to not bother thinking
         * further about this.
         */
        V rightValue = uncheckedCastNullableTToT(onlyOnRight.remove(leftKey));

                    l[i].delete();
                }
            } catch( SmbException se ) {
                /* Oracle FilesOnline version 9.0.4 doesn't send '.' and '..' so
                 * listFiles may generate undesireable "cannot find
                 * the file specified".
                 */
                if( se.getNtStatus() != SmbException.NT_STATUS_NO_SUCH_FILE ) {
                    throw se;
                }