@Override
        public int compare(Object baseObj1, long baseOff1, Object baseObj2, long baseOff2) {
            // TODO: Why are the sizes -1?
            row1.pointTo(baseObj1, baseOff1, -1);
            row2.pointTo(baseObj2, baseOff2, -1);
            return ordering.compare(row1, row2);
        }
Return the peak memory used so far, in bytes.
indexr-query-opt/src/main/java/org/apache/spark/sql/execution/UnsafeExternalRowSorter.java