Whether an entry can be used with the given environment: an entry marked
unavailable (available: false, which nothing implements) never is, as
SpeechProviderResolver already treats it; a local entry needs no key; any
other needs every one of its environment variables.
Whether an entry can be used with the given environment: an entry marked unavailable (
available: false, which nothing implements) never is, asSpeechProviderResolveralready treats it; a local entry needs no key; any other needs every one of its environment variables.