Autocomplete provider 'ClassProvider(undefined)' returns suggestions with a `prefix` attribute. The `prefix` attribute is now `replacementPrefix` and is optional. See https://github.com/atom/autocomplete-plus/wiki/Provider-API ``` AutocompleteManager.deprecateForSuggestion (<embedded>:11:646103) o.push.Promise.resolve.then.o (<embedded>:11:643877) <unknown> (null:null:null) ```