(Queue.Empty): When class based exceptions are in force, derive this class from the standard base exception Exception.  Otherwise define Queue.Empty as a string exception.
(Queue.Empty): When class based exceptions are in force, derive this
class from the standard base exception Exception.  Otherwise define
Queue.Empty as a string exception.

(Queue): 8-space to 4-space indentation conversion.  Also, basically
recast all method comments into docstrings.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator