code: static Matcher removeRepeatedStart(Matcher matcher) {
      if (matcher instanceof ZeroOrMoreMatcher) {
        ZeroOrMoreMatcher zm = matcher.as();
        if (zm.repeated() instanceof StartMatcher) {
          return zm.next();
        }
      }
      return matcher;
    }
docs: Zero or more start anchors is the same as not being anchored by the start.