* Support parallel test for understand_sentiment

* Full test on understand_sentiment

* Skip normal tests

* Debug CI

* Enable benchmark

* Revert init.cc

* Make CI pass

* Add unit-test and example

* Fix type error

* Fix unit test cases

* Fix init error for cudaplace

* Change unit-test options

* initial commit

* fix bug

* end of file fix

* address comments

* initial commit

* minor fix

* remove redundency

* address comments

* Save the inference model in Python example of recommender_system.

* Add infer() in Python unittest recommender_system.

* Add C++ inference unittest of recommender_system.

* Refine load

* Address review comments: round 1

* Make API consistent with python-save/load

* Add another unit test

* Remove commented function

* Fix GPU bug

* Address review comments

* Modify wrt PR 8147

* Fix filenames for combined case

* Fix typo

* Address review comments: round 2

* Unify TestInference by keeping default param in template

* Address review comment

* Fix spacing

* Fix parallel.do with batch norm

* Change log level

* CopyShare AllPlaces

* disable nccl test

* bring back parallel_do test

* set up python code

* fix bug

* add cc file

* fix cmake

* add inference test for label semantic role

* fix

* address comments

* address comments

* address comments

* address comments

* add use_cuda

* First basic implementation

* Add infer example for image_classification

* Address review comments: round 1

* add basic interface for learning rate decay
* add exponential_decay
* add natural_exp_decay
* add inverse_time_decay

Into one unit test file

* Polish sum_op support SelectedRows in_place

Enable whole-archive flag in cc_test and use cc_test to rewrite the CMakeLists.txt of inference unittest.

* remove pick dependency

* fix bug

* small fix

* modify executor.py for save and load

* clean code

* Add usage example

* refine executor run function

* fix bug

* refine executor code

* fix block bug

* fix comments

* fix bug

* fix pass num

Unify the recognize_digits

neural machine translation model support beam search with while op