book()["null"]=std::pair<synfig::Target::Factory,String>(Target_Null::create,"null");
ext_book()["null"]="null";
book()["null-tile"]=std::pair<synfig::Target::Factory,String>(Target_Null_Tile::create,"null-tile");
book()["null"]=std::pair<synfig::Target::Factory,String>(Target_Null::create,"null");
ext_book()["null"]="null";
book()["null-tile"]=std::pair<synfig::Target::Factory,String>(Target_Null_Tile::create,"null-tile");