docs: public void copyContent(final CharSequence buf, final ParserCursor cursor, final BitSet delimiters,
              final StringBuilder dst) {
          Args.notNull(buf, "Char sequence");
          Args.notNull(cursor, "Parser cursor");
          Args.notNull(dst, "String builder");
          int pos = cursor.getPos();
          final int indexFrom = cursor.getPos();
          final int indexTo = cursor.getUpperBound();
          for (int i = indexFrom; i < indexTo; i++) {
              final char current = buf.charAt(i);
              if ((delimiters != null && delimiters.get(current)) || isWhitespace(current)) {
                  break;
              }
              pos++;
              dst.append(current);
          }
          cursor.updatePos(pos);
      }