code: public final void init(String... packageNames) {
  
          Collection<Class<?>> classes = discoverClasses(packageNames);
          if (classes.isEmpty()) {
              log.warn("No annotated controllers found in package(s) '{}'", Arrays.toString(packageNames));
              return;
          }
  
          log.debug("Found {} controller classes in {} package(s)", classes.size(), packageNames.length);
  
          init(classes);
      }
docs: Scans, identifies, and registers annotated controller methods for the
  current runtime settings.
  
  @param packageNames