toJson method
Implementation
@override
Map<String, Object?> toJson() => {
if (reference != null) "reference": encodeValue(reference),
if (referenceKind != null) "reference_kind": encodeValue(referenceKind),
if (purpose != null) "purpose": encodeValue(purpose),
"file_id": encodeValue(fileId),
"field": encodeValue(field),
};