setSpellCheckerLanguages
The built in spellchecker does not automatically detect what language a user is typing in. In order for the spell checker to correctly check their words you must call this API with an array of language codes. You can get the list of supported language codes with the ses.availableSpellCheckerLanguages
property.
Note: On macOS the OS spellchecker is used and will detect your language automatically. This API is a no-op on macOS.