docs: protected boolean matchHeaderPattern(HttpMessage msg, String header, Pattern pattern) {
          if (msg.getResponseHeader().isEmpty()) {
              return false;
          }
  
          String val = msg.getResponseHeader().getHeader(header);
          if (val == null) {
              return false;
          }
  
          Matcher matcher = pattern.matcher(val);
          return matcher.find();
      }