Hi all,

I am trying to divide two 2D histograms created by RDataFrame, but it returns an error.

Small reproducible:

```
import ROOT
rdf = ROOT.RDataFrame(10)
rdf = rdf.Define("x", "rdfentry_").Define("y", "rdfentry_")
h1 = rdf.Histo2D(("h1", "title;x;y", 10, 0, 10, 10, 0, 10), "x", "y")
h2 = rdf.Histo2D(("h2", "title;x;y", 10, 0, 10, 10, 0, 10), "x", "y")
h1.Divide(h2)
```

output:

```
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: none of the 3 overloaded methods succeeded. Full details:
bool TH1::Divide(const TH1* h1) =>
TypeError: could not convert argument 1
bool TH1::Divide(TF1* f1, double c1 = 1) =>
TypeError: could not convert argument 1
bool TH1::Divide(const TH1* h1, const TH1* h2, double c1 = 1, double c2 = 1, const char* option = "") =>
TypeError: takes at least 2 arguments (1 given)
```

While simply:

```
>>> h1 = ROOT.TH2F("h1", "title;x;y", 10, 0, 10, 10,0, 10)
>>> h2 = ROOT.TH2F("h2", "title;x;y", 10, 0, 10, 10,0, 10)
>>> h1.Divide(h2)
True
```

Any thoughts?

cheers,

Bohdan