test_tree()
{
	TFile *f = new TFile("testtree.root", "RECREATE");
	TTree *t = new TTree("mytree", "mytree");

	char str[200];
	t->Branch("br", str, "br/C");

	strcpy(str, "");
	t->Fill();
	strcpy(str, "");
	t->Fill();
	strcpy(str, "aaaa");
	t->Fill();
	strcpy(str, "");
	t->Fill();
	strcpy(str, "");
	t->Fill();
	strcpy(str, "bbbbb");
	t->Fill();
	strcpy(str, "");
	t->Fill();
	strcpy(str, "");
	t->Fill();
	strcpy(str, "ccc");
	t->Fill();

	f->Write();
	f->Close();
}