* Fix indentations

* Change _add_special_tokens into staticmethod

* Change all tests of data module to unittest.TestCase

* Remove unused code

* Update README.md

* Add test for read_ui function

* Change tests of all datasets to unittest.TestCase

* Do not repeatedly showing split message in RatioSplit

* Change tests of eval_methods to unittest.TestCase

* Change tests of experiment to unittest.TestCase

* Change tests of metrics to unittest.TestCase

* Change tests of utils to unittest.TestCase

* Improve test coverage

* Fix indentations in test_trainset.py