block once this size has been reached, until queue items are consumed. If
*maxsize* is less than or equal to zero, the queue size is infinite.
+ .. versionadded:: 2.6
+
.. class:: PriorityQueue(maxsize)
Constructor for a priority queue. *maxsize* is an integer that sets the upperbound
one returned by ``sorted(list(entries))[0]``). A typical pattern for entries
is a tuple in the form: ``(priority_number, data)``.
+ .. versionadded:: 2.6
+
.. exception:: Empty
Exception raised when non-blocking :meth:`get` (or :meth:`get_nowait`) is called