code: @SuppressWarnings("unchecked")
      public static <T> Optional<Class<T>> optional(String dependency) {
          try {
              return Optional.of((Class<T>) Class.forName(dependency));
          } catch (ClassNotFoundException | NoClassDefFoundError e) {
              return Optional.empty();
          }
      }
docs: Checks if a class exists in the classpath.
  
  @param dependency class to look for.
  @return an {@link Optional} of the class (empty if class is not present).