code: public AsciiString trim() {
          int start = arrayOffset(), last = arrayOffset() + length() - 1;
          int end = last;
          while (start <= end && value[start] <= ' ') {
              start++;
          }
          while (end >= start && value[end] <= ' ') {
              end--;
          }
          if (start == 0 && end == last) {
              return this;
          }
          return new AsciiString(value, start, end - start + 1, false);
      }
docs: Duplicates this string removing white space characters from the beginning and end of the
  string, without copying.
  
  @return a new string with characters {@code <= \\u0020} removed from the beginning and the end.