toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (contentType != null) 'contentType': contentType!,
if (data != null) 'data': data!,
if (heightPx != null) 'heightPx': heightPx!,
if (widthPx != null) 'widthPx': widthPx!,
};