code: public static Slice leftTrim(Slice utf8, int[] whiteSpaceCodePoints)
      {
          int length = utf8.length();
  
          int position = firstNonMatchPosition(utf8, whiteSpaceCodePoints);
          return utf8.slice(position, length - position);
      }
docs: Removes all {@code whiteSpaceCodePoints} from the left side of the string.
  <p>
  Note: Invalid UTF-8 sequences are not trimmed.