Fixes part of #1725: [flake8] Remove unused imports in engine and contrib.engines

ignite/contrib/engines/common.py

@@ -1,7 +1,7 @@
 import numbers
 import warnings
 from functools import partial
-from typing import Any, Callable, Dict, Iterable, Mapping, Optional, Sequence, Tuple, Union, cast
+from typing import Any, Callable, Dict, Iterable, Mapping, Optional, Sequence, Union, cast
 
 import torch
 import torch.nn as nn
@@ -18,7 +18,6 @@
     PolyaxonLogger,
     ProgressBar,
     TensorboardLogger,
-    TrainsLogger,
     VisdomLogger,
     WandBLogger,
     global_step_from_engine,

ignite/engine/deterministic.py

@@ -2,7 +2,7 @@
 import warnings
 from collections import OrderedDict
 from functools import wraps
-from typing import Any, Callable, Generator, Iterator, List, Optional, cast
+from typing import Any, Callable, Generator, Iterator, List, Optional
 
 import torch
 from torch.utils.data import DataLoader

ignite/engine/events.py

@@ -1,5 +1,4 @@
 import numbers
-import warnings
 import weakref
 from enum import Enum
 from types import DynamicClassAttribute