#394: Try simpler solution to limit lines count

tests/test_shells.py

@@ -18,7 +18,7 @@ def history_lines(mocker):
     def aux(lines):
         mock = mocker.patch('io.open')
         mock.return_value.__enter__\
-            .return_value.__iter__.return_value = lines
+            .return_value.readlines.return_value = lines
     return aux