[DF][Doc][NFC] Show how to put RDataFrame in collections
[DF][Doc][NFC] Show how to put RDataFrame in collections

olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root