Coding constructor
Creates a new Coding instance.
Implementation
Coding({
Uri? system,
String? code,
String? display,
}) : this.fromJson(
JsonObject({
if (system != null) systemField.name: JsonString(system.toString()),
if (code != null) codeField.name: JsonString(code),
if (display != null) displayField.name: JsonString(display),
}),
);