Getting Template Variables through the API

I have a document with 5 Template Variables associated with it.

From a snippet called from the document’s content, I want to get the values of these 5 TV’s.

I see 3 getTemplateVar type functions documented on the API quick reference, but the parameters are not clearly documented. Knowing only the documentIdentifier and the name of the template variable, is it possible to get the value?

Otherwise I can pass in the values of these TV’s using parameters in the snippet, but that provides more opportunities for things to go wrong

If you want the raw values and other metadata, getTemplateVars(); if you want the output they should render on a page, getTemplateVarOutput().