My code opens an output file and creates one tree (with a couple of branches).
Does it make a difference how I save the information & close the file at the end of the job?
TFile::Write is interesting in case you have many objects in
file->GetList() collection in memory.
In case of one Tree, the two forms are equivalent. TFile::Write
makes a simple loop in the collection in memory.
see TTree::ChangeFile root.cern.ch/root/htmldoc/TTree. … ChangeFile
and the important Note at the end of this function in case
you write a large Tree.