docs: protected static void checkDirectory(boolean generateSouceOnly, File sourceOutputDir) {
          if (generateSouceOnly) {
              if (sourceOutputDir == null) {
                  throw new RuntimeException("param 'sourceOutputDir' is null.");
              }
  
              if (!sourceOutputDir.isDirectory()) {
                  throw new RuntimeException("param 'sourceOutputDir' should be a exist file directory.");
              }
          }
      }