Diff
Merge branch 'master' of https://github.com/neubig/webigator
Merge branch 'master' of https://github.com/neubig/webigator
Merge branch 'master' of https://github.com/neubig/webigator
Merge branch 'master' of https://github.com/neubig/webigator
Merge branch 'master' of https://github.com/neubig/webigator
Added a null classifier