This function combines
First the iterator is advanced to the next (possibly first) attribute.
If that fails, then
false is returned and there are no other
value are set to the name and value of the
attribute that has just been advanced to. At this point,
return the same values again.
The value returned in
name remains valid for as long as the iterator
remains at the current position. The value returned in
be unreffed using
g_variant_unref() when it is no longer in use.
the type of the attribute
the attribute value