Get tag from TextView

[Andrew Krause <andrew openldev org>]

I know this is probably an easy question, but anyway. Let's say I have a 
Gtk::TextBuffer. I want to find out if there is a tag applied to a 
character at offset some number or some iterator. If there is a tag 
applied to that character, then I want to see what tag is applied to 
that character. I hope that makes sense ... thanks for any suggestions! 
- Andrew