public Map<String, Long> getMetrics() {
      return metrics;
    }
The metric values in the map. The keys are the enum names (See: LlapDaemonExecutorInfo), and
the values are the actual values.
@return The metric map
llap-tez/src/java/org/apache/hadoop/hive/llap/tezplugins/metrics/LlapMetricsCollector.java