code: public <T extends MapLayer> Iterator<T> iterator(Class<T> type) {
  		return new LayerReaderIterator<>(type);
  	}
docs: Replies an iterator on the layers of the given type and read from the input stream.
  
  @param <T> the type of the layers to reply.
  @param type is the type of the layers to reply.
  @return the iterator.