public void shiftRightDestructive(int bits, boolean roundUp) {
    assert (bits >= 0);
    shiftRightDestructive(bits / 32, bits % 32, roundUp);
  }
Right-shift for the given number of bits. This version is destructive,
meaning it modifies this object.

@param bits
         the number of bits. must be positive
@param roundUp
         whether to round up the most significant bit that was discarded
common/src/java/org/apache/hadoop/hive/common/type/UnsignedInt128.java