diff --git a/LICENSES.md b/LICENSES.md
new file mode 100644
index 000000000..0964f8ffd
--- /dev/null
+++ b/LICENSES.md
@@ -0,0 +1,8 @@
+# Licenses for special operations
+
+In this file, we list the operations with other licenses instead of Apache 2.0. Users should be careful about adopting these operations in any commercial matters.
+
+| Operation | Files | License |
+| :--------------: | :-----------------------------------------------------------------------------------------------------------------------------------------: | :------------: |
+| upfirdn2d | [mmcv/ops/csrc/pytorch/upfirdn2d_kernel.cu](https://github.com/open-mmlab/mmcv/mmcv/ops/csrc/pytorch/upfirdn2d_kernel.cu) | NVIDIA License |
+| fused_leaky_relu | [mmcv/ops/csrc/pytorch/fused_bias_leakyrelu_cuda.cu](https://github.com/open-mmlab/mmcv/mmcv/ops/csrc/pytorch/fused_bias_leakyrelu_cuda.cu) | NVIDIA License |
diff --git a/README.md b/README.md
index 2180859a1..a8045e951 100644
--- a/README.md
+++ b/README.md
@@ -182,3 +182,7 @@ you may first refer to this [Trouble Shooting Page](https://mmcv.readthedocs.io/
## Contributing
We appreciate all contributions to improve MMCV. Please refer to [CONTRIBUTING.md](CONTRIBUTING.md) for the contributing guideline.
+
+## License
+
+MMCV is released under the Apache 2.0 license, while some specific operations in this library are with other licenses. Please refer to [LICENSES.md](LICENSES.md) for the careful check, if you are using our code for commercial matters.
diff --git a/README_zh-CN.md b/README_zh-CN.md
index b012af058..f12f5e449 100644
--- a/README_zh-CN.md
+++ b/README_zh-CN.md
@@ -179,6 +179,9 @@ c. 安装完整版并且编译 onnxruntime 的自定义算子
我们感谢所有的贡献者为改进和提升 MMCV 所作出的努力。请参考[贡献指南](CONTRIBUTING.md)来了解参与项目贡献的相关指引。
+## 许可证
+
+`MMCV` 目前以 Apache 2.0 的许可证发布，但是其中有一部分功能并不是使用的 Apache2.0 许可证，我们在 [许可证](LICENSES.md) 中详细地列出了这些功能以及他们对应的许可证，如果您正在从事盈利性活动，请谨慎参考此文档。
## 欢迎加入 OpenMMLab 社区
扫描下方的二维码可关注 OpenMMLab 团队的 [知乎官方账号](https://www.zhihu.com/people/openmmlab)，加入 OpenMMLab 团队的 [官方交流 QQ 群](https://jq.qq.com/?_wv=1027&k=aCvMxdr3)
diff --git a/mmcv/ops/csrc/pytorch/fused_bias_leakyrelu.cpp b/mmcv/ops/csrc/pytorch/fused_bias_leakyrelu.cpp
index 45637ad4f..702be12c6 100644
--- a/mmcv/ops/csrc/pytorch/fused_bias_leakyrelu.cpp
+++ b/mmcv/ops/csrc/pytorch/fused_bias_leakyrelu.cpp
@@ -1,6 +1,104 @@
// Modified from
-// from
// https://github.com/rosinality/stylegan2-pytorch/blob/master/op/fused_bias_act.cpp
+
+/*
+Copyright (c) 2021, NVIDIA Corporation. All rights reserved.
+
+NVIDIA Source Code License for StyleGAN2 with Adaptive Discriminator
+Augmentation (ADA)
+=======================================================================
+
+1. Definitions
+
+"Licensor" means any person or entity that distributes its Work.
+
+"Software" means the original work of authorship made available under
+this License.
+
+"Work" means the Software and any additions to or derivative works of
+the Software that are made available under this License.
+
+The terms "reproduce," "reproduction," "derivative works," and
+"distribution" have the meaning as provided under U.S. copyright law;
+provided, however, that for the purposes of this License, derivative
+works shall not include works that remain separable from, or merely
+link (or bind by name) to the interfaces of, the Work.
+
+Works, including the Software, are "made available" under this License
+by including in or with the Work either (a) a copyright notice
+referencing the applicability of this License to the Work, or (b) a
+copy of this License.
+
+2. License Grants
+
+ 2.1 Copyright Grant. Subject to the terms and conditions of this
+ License, each Licensor grants to you a perpetual, worldwide,
+ non-exclusive, royalty-free, copyright license to reproduce,
+ prepare derivative works of, publicly display, publicly perform,
+ sublicense and distribute its Work and any resulting derivative
+ works in any form.
+
+3. Limitations
+
+ 3.1 Redistribution. You may reproduce or distribute the Work only
+ if (a) you do so under this License, (b) you include a complete
+ copy of this License with your distribution, and (c) you retain
+ without modification any copyright, patent, trademark, or
+ attribution notices that are present in the Work.
+
+ 3.2 Derivative Works. You may specify that additional or different
+ terms apply to the use, reproduction, and distribution of your
+ derivative works of the Work ("Your Terms") only if (a) Your Terms
+ provide that the use limitation in Section 3.3 applies to your
+ derivative works, and (b) you identify the specific derivative
+ works that are subject to Your Terms. Notwithstanding Your Terms,
+ this License (including the redistribution requirements in Section
+ 3.1) will continue to apply to the Work itself.
+
+ 3.3 Use Limitation. The Work and any derivative works thereof only
+ may be used or intended for use non-commercially. Notwithstanding
+ the foregoing, NVIDIA and its affiliates may use the Work and any
+ derivative works commercially. As used herein, "non-commercially"
+ means for research or evaluation purposes only.
+
+ 3.4 Patent Claims. If you bring or threaten to bring a patent claim
+ against any Licensor (including any claim, cross-claim or
+ counterclaim in a lawsuit) to enforce any patents that you allege
+ are infringed by any Work, then your rights under this License from
+ such Licensor (including the grant in Section 2.1) will terminate
+ immediately.
+
+ 3.5 Trademarks. This License does not grant any rights to use any
+ Licensor’s or its affiliates’ names, logos, or trademarks, except
+ as necessary to reproduce the notices described in this License.
+
+ 3.6 Termination. If you violate any term of this License, then your
+ rights under this License (including the grant in Section 2.1) will
+ terminate immediately.
+
+4. Disclaimer of Warranty.
+
+THE WORK IS PROVIDED "AS IS" WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WARRANTIES OR CONDITIONS OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE OR
+NON-INFRINGEMENT. YOU BEAR THE RISK OF UNDERTAKING ANY ACTIVITIES UNDER
+THIS LICENSE.
+
+5. Limitation of Liability.
+
+EXCEPT AS PROHIBITED BY APPLICABLE LAW, IN NO EVENT AND UNDER NO LEGAL
+THEORY, WHETHER IN TORT (INCLUDING NEGLIGENCE), CONTRACT, OR OTHERWISE
+SHALL ANY LICENSOR BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY DIRECT,
+INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF
+OR RELATED TO THIS LICENSE, THE USE OR INABILITY TO USE THE WORK
+(INCLUDING BUT NOT LIMITED TO LOSS OF GOODWILL, BUSINESS INTERRUPTION,
+LOST PROFITS OR DATA, COMPUTER FAILURE OR MALFUNCTION, OR ANY OTHER
+COMMERCIAL DAMAGES OR LOSSES), EVEN IF THE LICENSOR HAS BEEN ADVISED OF
+THE POSSIBILITY OF SUCH DAMAGES.
+
+=======================================================================
+*/
+
#include "pytorch_cpp_helper.hpp"
#ifdef MMCV_WITH_CUDA
diff --git a/mmcv/ops/csrc/pytorch/fused_bias_leakyrelu_cuda.cu b/mmcv/ops/csrc/pytorch/fused_bias_leakyrelu_cuda.cu
index cde947de4..911ea019a 100644
--- a/mmcv/ops/csrc/pytorch/fused_bias_leakyrelu_cuda.cu
+++ b/mmcv/ops/csrc/pytorch/fused_bias_leakyrelu_cuda.cu
@@ -1,4 +1,4 @@
-// from
+// Modified from
// https://github.com/rosinality/stylegan2-pytorch/blob/master/op/fused_bias_act_kernel.cu
// Copyright (c) 2019, NVIDIA Corporation. All rights reserved.
//
diff --git a/mmcv/ops/csrc/pytorch/upfirdn2d.cpp b/mmcv/ops/csrc/pytorch/upfirdn2d.cpp
index 44322a121..a3ed139e7 100644
--- a/mmcv/ops/csrc/pytorch/upfirdn2d.cpp
+++ b/mmcv/ops/csrc/pytorch/upfirdn2d.cpp
@@ -1,5 +1,104 @@
-// from
+// Modified from
// https://github.com/rosinality/stylegan2-pytorch/blob/master/op/upfirdn2d.cpp
+
+/*
+Copyright (c) 2021, NVIDIA Corporation. All rights reserved.
+
+NVIDIA Source Code License for StyleGAN2 with Adaptive Discriminator
+Augmentation (ADA)
+=======================================================================
+
+1. Definitions
+
+"Licensor" means any person or entity that distributes its Work.
+
+"Software" means the original work of authorship made available under
+this License.
+
+"Work" means the Software and any additions to or derivative works of
+the Software that are made available under this License.
+
+The terms "reproduce," "reproduction," "derivative works," and
+"distribution" have the meaning as provided under U.S. copyright law;
+provided, however, that for the purposes of this License, derivative
+works shall not include works that remain separable from, or merely
+link (or bind by name) to the interfaces of, the Work.
+
+Works, including the Software, are "made available" under this License
+by including in or with the Work either (a) a copyright notice
+referencing the applicability of this License to the Work, or (b) a
+copy of this License.
+
+2. License Grants
+
+ 2.1 Copyright Grant. Subject to the terms and conditions of this
+ License, each Licensor grants to you a perpetual, worldwide,
+ non-exclusive, royalty-free, copyright license to reproduce,
+ prepare derivative works of, publicly display, publicly perform,
+ sublicense and distribute its Work and any resulting derivative
+ works in any form.
+
+3. Limitations
+
+ 3.1 Redistribution. You may reproduce or distribute the Work only
+ if (a) you do so under this License, (b) you include a complete
+ copy of this License with your distribution, and (c) you retain
+ without modification any copyright, patent, trademark, or
+ attribution notices that are present in the Work.
+
+ 3.2 Derivative Works. You may specify that additional or different
+ terms apply to the use, reproduction, and distribution of your
+ derivative works of the Work ("Your Terms") only if (a) Your Terms
+ provide that the use limitation in Section 3.3 applies to your
+ derivative works, and (b) you identify the specific derivative
+ works that are subject to Your Terms. Notwithstanding Your Terms,
+ this License (including the redistribution requirements in Section
+ 3.1) will continue to apply to the Work itself.
+
+ 3.3 Use Limitation. The Work and any derivative works thereof only
+ may be used or intended for use non-commercially. Notwithstanding
+ the foregoing, NVIDIA and its affiliates may use the Work and any
+ derivative works commercially. As used herein, "non-commercially"
+ means for research or evaluation purposes only.
+
+ 3.4 Patent Claims. If you bring or threaten to bring a patent claim
+ against any Licensor (including any claim, cross-claim or
+ counterclaim in a lawsuit) to enforce any patents that you allege
+ are infringed by any Work, then your rights under this License from
+ such Licensor (including the grant in Section 2.1) will terminate
+ immediately.
+
+ 3.5 Trademarks. This License does not grant any rights to use any
+ Licensor’s or its affiliates’ names, logos, or trademarks, except
+ as necessary to reproduce the notices described in this License.
+
+ 3.6 Termination. If you violate any term of this License, then your
+ rights under this License (including the grant in Section 2.1) will
+ terminate immediately.
+
+4. Disclaimer of Warranty.
+
+THE WORK IS PROVIDED "AS IS" WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WARRANTIES OR CONDITIONS OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE OR
+NON-INFRINGEMENT. YOU BEAR THE RISK OF UNDERTAKING ANY ACTIVITIES UNDER
+THIS LICENSE.
+
+5. Limitation of Liability.
+
+EXCEPT AS PROHIBITED BY APPLICABLE LAW, IN NO EVENT AND UNDER NO LEGAL
+THEORY, WHETHER IN TORT (INCLUDING NEGLIGENCE), CONTRACT, OR OTHERWISE
+SHALL ANY LICENSOR BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY DIRECT,
+INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF
+OR RELATED TO THIS LICENSE, THE USE OR INABILITY TO USE THE WORK
+(INCLUDING BUT NOT LIMITED TO LOSS OF GOODWILL, BUSINESS INTERRUPTION,
+LOST PROFITS OR DATA, COMPUTER FAILURE OR MALFUNCTION, OR ANY OTHER
+COMMERCIAL DAMAGES OR LOSSES), EVEN IF THE LICENSOR HAS BEEN ADVISED OF
+THE POSSIBILITY OF SUCH DAMAGES.
+
+=======================================================================
+*/
+
#include "pytorch_cpp_helper.hpp"
#ifdef MMCV_WITH_CUDA
diff --git a/mmcv/ops/csrc/pytorch/upfirdn2d_kernel.cu b/mmcv/ops/csrc/pytorch/upfirdn2d_kernel.cu
index 52a175bfd..ea2f08820 100644
--- a/mmcv/ops/csrc/pytorch/upfirdn2d_kernel.cu
+++ b/mmcv/ops/csrc/pytorch/upfirdn2d_kernel.cu
@@ -1,4 +1,4 @@
-// from
+// Modified from
// https://github.com/rosinality/stylegan2-pytorch/blob/master/op/upfirdn2d_kernel.cu
// Copyright (c) 2019, NVIDIA Corporation. All rights reserved.
//
diff --git a/mmcv/ops/fused_bias_leakyrelu.py b/mmcv/ops/fused_bias_leakyrelu.py
index 87630ff43..c2bf7b4f0 100644
--- a/mmcv/ops/fused_bias_leakyrelu.py
+++ b/mmcv/ops/fused_bias_leakyrelu.py
@@ -1,4 +1,99 @@
-# modify from https://github.com/rosinality/stylegan2-pytorch/blob/master/op/fused_act.py # noqa:E501
+# modified from https://github.com/rosinality/stylegan2-pytorch/blob/master/op/fused_act.py # noqa:E501
+
+# Copyright (c) 2021, NVIDIA Corporation. All rights reserved.
+# NVIDIA Source Code License for StyleGAN2 with Adaptive Discriminator
+# Augmentation (ADA)
+# =======================================================================
+
+# 1. Definitions
+
+# "Licensor" means any person or entity that distributes its Work.
+
+# "Software" means the original work of authorship made available under
+# this License.
+
+# "Work" means the Software and any additions to or derivative works of
+# the Software that are made available under this License.
+
+# The terms "reproduce," "reproduction," "derivative works," and
+# "distribution" have the meaning as provided under U.S. copyright law;
+# provided, however, that for the purposes of this License, derivative
+# works shall not include works that remain separable from, or merely
+# link (or bind by name) to the interfaces of, the Work.
+
+# Works, including the Software, are "made available" under this License
+# by including in or with the Work either (a) a copyright notice
+# referencing the applicability of this License to the Work, or (b) a
+# copy of this License.
+
+# 2. License Grants
+
+# 2.1 Copyright Grant. Subject to the terms and conditions of this
+# License, each Licensor grants to you a perpetual, worldwide,
+# non-exclusive, royalty-free, copyright license to reproduce,
+# prepare derivative works of, publicly display, publicly perform,
+# sublicense and distribute its Work and any resulting derivative
+# works in any form.
+
+# 3. Limitations
+
+# 3.1 Redistribution. You may reproduce or distribute the Work only
+# if (a) you do so under this License, (b) you include a complete
+# copy of this License with your distribution, and (c) you retain
+# without modification any copyright, patent, trademark, or
+# attribution notices that are present in the Work.
+
+# 3.2 Derivative Works. You may specify that additional or different
+# terms apply to the use, reproduction, and distribution of your
+# derivative works of the Work ("Your Terms") only if (a) Your Terms
+# provide that the use limitation in Section 3.3 applies to your
+# derivative works, and (b) you identify the specific derivative
+# works that are subject to Your Terms. Notwithstanding Your Terms,
+# this License (including the redistribution requirements in Section
+# 3.1) will continue to apply to the Work itself.
+
+# 3.3 Use Limitation. The Work and any derivative works thereof only
+# may be used or intended for use non-commercially. Notwithstanding
+# the foregoing, NVIDIA and its affiliates may use the Work and any
+# derivative works commercially. As used herein, "non-commercially"
+# means for research or evaluation purposes only.
+
+# 3.4 Patent Claims. If you bring or threaten to bring a patent claim
+# against any Licensor (including any claim, cross-claim or
+# counterclaim in a lawsuit) to enforce any patents that you allege
+# are infringed by any Work, then your rights under this License from
+# such Licensor (including the grant in Section 2.1) will terminate
+# immediately.
+
+# 3.5 Trademarks. This License does not grant any rights to use any
+# Licensor’s or its affiliates’ names, logos, or trademarks, except
+# as necessary to reproduce the notices described in this License.
+
+# 3.6 Termination. If you violate any term of this License, then your
+# rights under this License (including the grant in Section 2.1) will
+# terminate immediately.
+
+# 4. Disclaimer of Warranty.
+
+# THE WORK IS PROVIDED "AS IS" WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WARRANTIES OR CONDITIONS OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE OR
+# NON-INFRINGEMENT. YOU BEAR THE RISK OF UNDERTAKING ANY ACTIVITIES UNDER
+# THIS LICENSE.
+
+# 5. Limitation of Liability.
+
+# EXCEPT AS PROHIBITED BY APPLICABLE LAW, IN NO EVENT AND UNDER NO LEGAL
+# THEORY, WHETHER IN TORT (INCLUDING NEGLIGENCE), CONTRACT, OR OTHERWISE
+# SHALL ANY LICENSOR BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY DIRECT,
+# INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF
+# OR RELATED TO THIS LICENSE, THE USE OR INABILITY TO USE THE WORK
+# (INCLUDING BUT NOT LIMITED TO LOSS OF GOODWILL, BUSINESS INTERRUPTION,
+# LOST PROFITS OR DATA, COMPUTER FAILURE OR MALFUNCTION, OR ANY OTHER
+# COMMERCIAL DAMAGES OR LOSSES), EVEN IF THE LICENSOR HAS BEEN ADVISED OF
+# THE POSSIBILITY OF SUCH DAMAGES.
+
+# =======================================================================
import torch
import torch.nn.functional as F
diff --git a/mmcv/ops/upfirdn2d.py b/mmcv/ops/upfirdn2d.py
index 33f272236..1de193d8a 100644
--- a/mmcv/ops/upfirdn2d.py
+++ b/mmcv/ops/upfirdn2d.py
@@ -1,4 +1,99 @@
-# modify from https://github.com/rosinality/stylegan2-pytorch/blob/master/op/upfirdn2d.py # noqa:E501
+# modified from https://github.com/rosinality/stylegan2-pytorch/blob/master/op/upfirdn2d.py # noqa:E501
+
+# Copyright (c) 2021, NVIDIA Corporation. All rights reserved.
+# NVIDIA Source Code License for StyleGAN2 with Adaptive Discriminator
+# Augmentation (ADA)
+# =======================================================================
+
+# 1. Definitions
+
+# "Licensor" means any person or entity that distributes its Work.
+
+# "Software" means the original work of authorship made available under
+# this License.
+
+# "Work" means the Software and any additions to or derivative works of
+# the Software that are made available under this License.
+
+# The terms "reproduce," "reproduction," "derivative works," and
+# "distribution" have the meaning as provided under U.S. copyright law;
+# provided, however, that for the purposes of this License, derivative
+# works shall not include works that remain separable from, or merely
+# link (or bind by name) to the interfaces of, the Work.
+
+# Works, including the Software, are "made available" under this License
+# by including in or with the Work either (a) a copyright notice
+# referencing the applicability of this License to the Work, or (b) a
+# copy of this License.
+
+# 2. License Grants
+
+# 2.1 Copyright Grant. Subject to the terms and conditions of this
+# License, each Licensor grants to you a perpetual, worldwide,
+# non-exclusive, royalty-free, copyright license to reproduce,
+# prepare derivative works of, publicly display, publicly perform,
+# sublicense and distribute its Work and any resulting derivative
+# works in any form.
+
+# 3. Limitations
+
+# 3.1 Redistribution. You may reproduce or distribute the Work only
+# if (a) you do so under this License, (b) you include a complete
+# copy of this License with your distribution, and (c) you retain
+# without modification any copyright, patent, trademark, or
+# attribution notices that are present in the Work.
+
+# 3.2 Derivative Works. You may specify that additional or different
+# terms apply to the use, reproduction, and distribution of your
+# derivative works of the Work ("Your Terms") only if (a) Your Terms
+# provide that the use limitation in Section 3.3 applies to your
+# derivative works, and (b) you identify the specific derivative
+# works that are subject to Your Terms. Notwithstanding Your Terms,
+# this License (including the redistribution requirements in Section
+# 3.1) will continue to apply to the Work itself.
+
+# 3.3 Use Limitation. The Work and any derivative works thereof only
+# may be used or intended for use non-commercially. Notwithstanding
+# the foregoing, NVIDIA and its affiliates may use the Work and any
+# derivative works commercially. As used herein, "non-commercially"
+# means for research or evaluation purposes only.
+
+# 3.4 Patent Claims. If you bring or threaten to bring a patent claim
+# against any Licensor (including any claim, cross-claim or
+# counterclaim in a lawsuit) to enforce any patents that you allege
+# are infringed by any Work, then your rights under this License from
+# such Licensor (including the grant in Section 2.1) will terminate
+# immediately.
+
+# 3.5 Trademarks. This License does not grant any rights to use any
+# Licensor’s or its affiliates’ names, logos, or trademarks, except
+# as necessary to reproduce the notices described in this License.
+
+# 3.6 Termination. If you violate any term of this License, then your
+# rights under this License (including the grant in Section 2.1) will
+# terminate immediately.
+
+# 4. Disclaimer of Warranty.
+
+# THE WORK IS PROVIDED "AS IS" WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WARRANTIES OR CONDITIONS OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE OR
+# NON-INFRINGEMENT. YOU BEAR THE RISK OF UNDERTAKING ANY ACTIVITIES UNDER
+# THIS LICENSE.
+
+# 5. Limitation of Liability.
+
+# EXCEPT AS PROHIBITED BY APPLICABLE LAW, IN NO EVENT AND UNDER NO LEGAL
+# THEORY, WHETHER IN TORT (INCLUDING NEGLIGENCE), CONTRACT, OR OTHERWISE
+# SHALL ANY LICENSOR BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY DIRECT,
+# INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF
+# OR RELATED TO THIS LICENSE, THE USE OR INABILITY TO USE THE WORK
+# (INCLUDING BUT NOT LIMITED TO LOSS OF GOODWILL, BUSINESS INTERRUPTION,
+# LOST PROFITS OR DATA, COMPUTER FAILURE OR MALFUNCTION, OR ANY OTHER
+# COMMERCIAL DAMAGES OR LOSSES), EVEN IF THE LICENSOR HAS BEEN ADVISED OF
+# THE POSSIBILITY OF SUCH DAMAGES.
+
+# =======================================================================
import torch
from torch.autograd import Function