Update 01. Workers.py

Author: MitkoVtori

OOP/7.SOLID/SOLID - Exercise/01. Workers.py

@@ -22,7 +22,7 @@ def __init__(self):
         self.worker = None
 
     def set_worker(self, worker):
-        assert isinstance(worker, BaseWorker), '`worker` must be of type {}'.format(Worker)
+        assert isinstance(worker, BaseWorker), '`worker` must be of type {}'.format(BaseWorker)
 
         self.worker = worker