@Override
        public ITileLayer createTileLayer(final TileCache tileCache, final MapViewPosition mapViewPosition) {
            final List<MapFile> mapFiles = new ArrayList<>();
            for (ImmutablePair<String, Uri> fileName : mapUris) {
                final InputStream mapStream = createMapFileInputStream(fileName.right);
                if (mapStream == null) {
                    continue;
                }
                final MapFile mf = createMapFile(String.valueOf(fileName.right), mapStream);
                if (mf != null) {
                    mapFiles.add(mf);
                } else {
                    MapsforgeMapProvider.getInstance().invalidateMapUri(fileName.right);
                }
            }

            return new MultiRendererLayer(tileCache, mapFiles, mapViewPosition, false, true, false, AndroidGraphicFactory.INSTANCE);
        }
Create new render layer, if mapfiles exist
main/src/main/java/cgeo/geocaching/maps/mapsforge/MapsforgeMapProvider.java