timezoneProvider property
All known TZ database timezone identifiers associated with the timezones.
It may be replaced to support other timezone sources.
Retrieving a timezone directly from this map is discouraged. Users should prefer Timezone.new.
The default implementation is unmodifiable and lazy. Iterating over the entries/values is discouraged since it will initialize the iterated Timezones, thereby increasing memory footprint. However, iterating over the keys is fine.
Implementation
static Map<String, Timezone> timezoneProvider = DefaultTimezoneProvider();