@Override
      public int compare(JsonObject a, JsonObject b) {
        Long valA = a.get(KEY_NAME).getAsLong();
        Long valB = b.get(KEY_NAME).getAsLong();
        return valA.compareTo(valB);
      }
Sort the JsonArray given in parameters, based on the flowtime property,
from the most recent to the oldest.
app/com/linkedin/drelephant/util/Utils.java