2/n Consolidate collective functions - collective base and subclasses

Author: four4fish

pytorch_lightning/plugins/collective/__init__.py

@@ -0,0 +1,18 @@
+# Copyright The PyTorch Lightning team.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from pytorch_lightning.plugins.collective.collective_plugin import Collective  # noqa: F401
+from pytorch_lightning.plugins.collective.single_device_collective import SingleNodeCollective  # noqa: F401
+from pytorch_lightning.plugins.collective.torch_collective import TorchCollective  # noqa: F401
+from pytorch_lightning.plugins.collective.horovod_collective import HorovodCollective  # noqa: F401
+from pytorch_lightning.plugins.collective.tpu_collective import TPUCollective  # noqa: F401