code: private void addTypes(Injector injector, List<Class<?>> types) {
          for (Binding<?> binding : injector.getBindings().values()) {
              Key<?> key = binding.getKey();
              Type type = key.getTypeLiteral().getType();
              if (hasAnnotatedMethods(type)) {
                  types.add(((Class<?>)type));
              }
          }
          if (injector.getParent() != null) {
              addTypes(injector.getParent(), types);
          }
      }
docs: Adds steps types from given injector and recursively its parent
  
  @param injector the current Inject
  @param types the List of steps types