refactor(follower): better logs for stopping iterator

Author: eiri

ibmcloudant/features/changes_follower.py

@@ -182,7 +182,8 @@ def _request_callback(self):
                     [ChangesResultItem.from_dict(item) for item in results]
                 )
             except Exception as e:
-                self.logger.debug(f'Exception getting changes {e}')
+                if type(e) is not StopIteration:
+                    self.logger.debug(f'Exception getting changes {e}')
                 if (
                     self._transient_suppression == _TransientErrorSuppression.NEVER
                     or (
@@ -200,7 +201,10 @@ def _request_callback(self):
                     type(e) is ApiException and e.status_code in [400, 401, 403, 404]
                     or type(e) is StopIteration
                 ):
-                    self.logger.debug('Terminal error.')
+                    if type(e) is StopIteration:
+                        self.logger.debug('Iterator stopped.')
+                    else:
+                        self.logger.debug('Terminal error.')
                     self._buffer.join()
                     self._buffer.put(e)
                     break