docs: static Matcher convertRepeatedAnyCharSeqToIndexOf(Matcher matcher) {
      if (matcher instanceof ZeroOrMoreMatcher) {
        ZeroOrMoreMatcher zm1 = matcher.as();
        Matcher prefix = PatternUtils.getPrefix(zm1.next());
        if (zm1.repeated() instanceof AnyMatcher && prefix instanceof CharSeqMatcher) {
          String pattern = prefix.<CharSeqMatcher>as().pattern();
          Matcher suffix = PatternUtils.getSuffix(zm1.next());
          return new IndexOfMatcher(pattern, suffix);
        }
      }
      return matcher;
    }