@Override
  public String toString() {
    StringBuilder str = new StringBuilder();
    str.append("Int128: count=" + count + ",");
    str.append("v[0]=" + v[0] + "(0x" + Integer.toHexString(v[0]) + "), ");
    str.append("v[1]=" + v[1] + "(0x" + Integer.toHexString(v[1]) + "), ");
    str.append("v[2]=" + v[2] + "(0x" + Integer.toHexString(v[2]) + "), ");
    str.append("v[3]=" + v[3] + "(0x" + Integer.toHexString(v[3]) + "), ");
    str.append("BigInteger#toString=" + toBigIntegerSlow().toString());
    return new String(str);
  }
Similar to {@link #toFormalString()} but returns an array of digits
instead of string. The length of the array and the count of trailing
zeros are returned in the array passed at first and second positions
respectively.
@param meta Array of size two that is populated with length of the returned array
            and the count of trailing zeros.
@return Digits of the this value
@throws NullPointerException if meta is null.
@throws ArrayIndexOutOfBoundsException if meta is less than size two.
common/src/java/org/apache/hadoop/hive/common/type/UnsignedInt128.java