comments `#` not supported

When trying to parse a service which contains a comment, the following error is raised

```
TypeError: Cannot set properties of undefined (setting '# failing')
```

Reproduce the parser failure with a service containing a `#` comment, then inspect the parser entry point and existing parsing tests, if present. Confirm the intended comment behavior before changing it; the issue is done when that input parses without the reported TypeError and the behavior is covered by a regression test.

Written by the indexing model from the issue text.