Attempts to advance the iterator to the next (possibly first)
attribute.
%TRUE is returned on success, or %FALSE if there are no more
attributes.
You must call this function when you first acquire the iterator
to advance it to the first attribute (and determine if the first
attribute exists at all).
Attempts to advance the iterator to the next (possibly first) attribute.
%TRUE is returned on success, or %FALSE if there are no more attributes.
You must call this function when you first acquire the iterator to advance it to the first attribute (and determine if the first attribute exists at all).