env property
Env is REQUIRED and must be main, test or dev. A bare call does not default to production, which is what closes the fat-finger and confused-deputy hazard. It carries no validate:\"required\": the handler already refuses an empty env with the sentence that names the three values, and a validator tag would replace that sentence with a generic one. The requirement is stated here and enforced there, once.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
String? env;