after running isort

Change-Id: I6d7dbb8dee9480fc9242529089a1b40f17f068e7
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/25052
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

secop/poller.py

@@ -34,10 +34,11 @@ Usage examples:
 """
 
 import time
-from threading import Event
 from heapq import heapify, heapreplace
-from secop.lib import mkthread
+from threading import Event
+
 from secop.errors import ProgrammingError
+from secop.lib import mkthread
 
 # poll types:
 AUTO = 1  #: equivalent to True, converted to REGULAR, SLOW or DYNAMIC