@SuppressWarnings("UseOfSystemOutOrSystemErr")
    public void printPerfMetrics() {
        if (!enablePerfMetrics) {
            throw new IllegalStateException("Perf metrics not enabled");
        }
        System.out.println("Average probes per lookup: " + map.getAverageProbesPerLookup());
        System.out.println("Number of hash collisions: " + map.getNumHashCollisions());
        System.out.println("Time spent resizing (ns): " + map.getTimeSpentResizingNs());
        System.out.println("Total memory consumption (bytes): " + map.getTotalMemoryConsumption());
    }
Free the memory associated with this map. This is idempotent and can be called multiple times.
indexr-query-opt/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java