Since this pattern consists of `\w+`, consideration to `_` is missing. Moreover, it does not correspond to the `<<<"heredoc"` style. <img width="152" alt="2018-03-10 0 53 23" src="https://user-images.githubusercontent.com/822086/37216168-7d482ca8-23fd-11e8-8f5c-e0e13b438dec.png"> <img width="159" alt="2018-03-10 0 55 02" src="https://user-images.githubusercontent.com/822086/37216252-b66b1efa-23fd-11e8-9d61-84f75b80c2ba.png">