operator [] method Null safety
- String? propertyName
Retrieves a value by property name from backing.
Implementation
dynamic operator [](String? propertyName) {
final prop = properties[propertyName];
if (prop == null) {
throw ArgumentError("Invalid property access for '${entity.name}'. "
"Property '$propertyName' does not exist on '${entity.name}'.");
}
return backing.valueForProperty(prop);
}