docs: public <T> void setState(HttpConnectionInterceptor interceptor, String stateName, T
              stateObjectToStore) {
          Map<String, Object> state = interceptorStates.get(interceptor);
          if (state == null) {
              interceptorStates.put(interceptor, (state = new ConcurrentHashMap<String, Object>()));
          }
          state.put(stateName, stateObjectToStore);
      }