explicitJsonNullWhenNonNullField property
Enables PATCH-style tri-state semantics for this field.
When true, generated toJson omits the JSON key only when the Dart
field is null, but still writes "key": null when the field is
non-null and serialization yields JSON null.
Generated fromJson uses Map.containsKey to distinguish a missing key
(typically decoded as Dart null on a nullable field) from an explicit
JSON null (decoded via the field's fromJson path with a null
argument). The field type must be nullable, and any custom fromJson
function must accept a nullable JSON input for the explicit-null case.
Cannot be combined with disallowNullValue, required, defaultValue,
or readValue. Setting this flag to true overrides includeIfNull.
Implementation
final bool? explicitJsonNullWhenNonNullField;