code: @Override
      public <E extends R> boolean exists(final UniqueKey<E> uniqueKey) {
          boolean res;
  
          synchronized (this.componentMap) {
              // Check from singleton map it he key exists and if the weak reference is not null
              res = this.componentMap.containsKey(uniqueKey) && !this.componentMap.get(uniqueKey).isEmpty();
          }
  
          return res;
      }
docs: {@inheritDoc}