@Override
        public LongAdder read(JsonReader in) throws IOException {
          LongAdder value = new LongAdder();
          value.add(in.nextLong());
          return value;
        }
Create a builder which is used to create a Gson instance.
<p/>
Will set some common configs for the builder.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/GsonUtil.java