React eslint not catching the use of underscore with internal methods

In the [React/JSX Styleguide 'Methods' section](https://github.com/airbnb/javascript/blob/master/react/README.md#methods) it says you shouldn't use `_` to prefix internal methods. However, some of my code contains this convention and it isn't being caught by the linter. I double-checked the eslint rules for react/jsx files and there doesn't seem to be a rule defined for this convention.

Is this intentional? If so, why specify the rule in your documentation? I found a related issue (#490), but it wasn't clearly stated whether or not this rule should definitely be adhered to but rather that it's more or less up to the programmer.

Any clarification would be greatly appreciated.

Inizia con la sezione «Methods» di React/JSX Styleguide in react/README.md ed esamina le regole ESLint esistenti per i file React/JSX. Esamina la issue #490 correlata e determina se la convenzione documentata dell’underscore debba essere applicata; il lavoro è completato quando è stata definita una policy e sono state apportate le relative modifiche alla documentazione o al linting.

Scritto dal modello di indicizzazione a partire dal testo della issue.