optionalConfiguration top-level constant Null safety

ConfigurationItemAttribute const optionalConfiguration
@Deprecated("Use `nullable` property")

A ConfigurationItemAttribute for optional properties.

NOTICE: This will be removed in version 2.0.0. To signify required or optional config you could do: Example:

class MyConfig extends Config {
   late String required;
   String? optional;
   String optionalWithDefult = 'default';
   late String optionalWithComputedDefault = _default();

   String _default() => 'computed';


@Deprecated("Use `nullable` property")
const ConfigurationItemAttribute optionalConfiguration =