private void updateCount() {
    if (v[3] != 0) {
      this.count = (byte) 4;
    } else if (v[2] != 0) {
      this.count = (byte) 3;
    } else if (v[1] != 0) {
      this.count = (byte) 2;
    } else if (v[0] != 0) {
      this.count = (byte) 1;
    } else {
      this.count = (byte) 0;
    }
  }
Updates the value of {@link #count} by checking {@link #v}.
common/src/java/org/apache/hadoop/hive/common/type/UnsignedInt128.java