Indicates whether the element name is one for which empty values should
be recorded.
If there were many tags that support empty values, it might make sense to
have a constant list that contains all those tag names. Then this method
would search the list for the target elementName. Because this code
is potentially invoked for many elements that do not support empty values,
and because the list is very small at the moment, the current
implementation uses an inelegant but fast equals test.
If the set of tags that should support empty values grows a little,
extending the expression to
elementName.equals(TAG_1) || elementName.equals(TAG_2) || ...
might make sense. If the set of such tags grows sufficiently large, then
a list-based approach might make more sense even though it might prove
to be slower.