in the same fashion), or a filehandle GLOB. Catalyst
will write it piece by piece into the response.
+When using a L<IO::Handle> type of object and no content length has been
+already set in the response headers Catalyst will make a reasonable attempt
+to determine the size of the Handle. Depending on the implementation of your
+handle object, setting the content length may fail. If it is at all possible
+for you to determine the content length of your handle object,
+it is recomended that you set the content length in the response headers
+yourself, which will be respected and sent by Catalyst in the response.
+
=head2 $res->has_body
Predicate which returns true when a body has been set.