toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (author != null) 'author': author!,
if (imageUrl != null) 'imageUrl': imageUrl!,
if (referenceUrl != null) 'referenceUrl': referenceUrl!,
if (resourceId != null) 'resourceId': resourceId!,
if (type != null) 'type': type!,
};