Part of bzrlib.export
|Function||dir_exporter_generator||Return a generator that exports this tree to a new directory.|
dest should either not exist or should be empty. If it does not exist it
will be created holding the contents of this tree.
|Parameters||fileobj||Is not used in this exporter|
|Note||If the export fails, the destination directory will be left in an incompletely exported state: export is not transactional.|