`Twig_Node_Expression_GetAttr` does a `$this->getAttribute()` so I don't think it's the right Expression to use or maybe I don't get it...
`Twig_Node_Expression_Name` calls `compiler::string` so it escapes `"`.
`Twig_Node_Expression_Constant` calls `compiler::repr` which calls `compiler::string` so it escapes `$`.

Any idea?