public void shiftLeftDestructive(int bits) {
    assert (bits >= 0);
    shiftLeftDestructive(bits / 32, bits % 32);
  }
Left-shift for the given number of bits. This method does not throw an
error even if overflow happens. This version is destructive, meaning it
modifies this object.

@param bits
         the number of bits. must be positive
common/src/java/org/apache/hadoop/hive/common/type/UnsignedInt128.java