docs: private RestEndpointGroup getEndpointGroup(String commandLine) {
          if (commandLine == null) {
              return null;
          }
          StringTokenizer st = new StringTokenizer(commandLine);
          String operation = nextToken(st);
          // If the operation doesn't have a parser, then it's unknown.
          if (parsers.getParser(operation) == null) {
              return null;
          }
          // the operation is a HTTP method so the next token should be a resource path
          String requestUri = nextToken(st);
          return requestUri != null ? getHttpApiEndpointGroup(operation, requestUri) : null;
      }