private static boolean hasSecondVInt(byte b) {
    return WritableUtils.isNegativeVInt(b);
  }
Given an integer representing nanoseconds, write its serialized
value to the byte array b at offset

@param nanos
@param b
@param offset
@return
serde/src/java/org/apache/hadoop/hive/serde2/io/TimestampLocalTZWritable.java