call method
Implementation
@override
Object? call(Interpreter interpreter, List<Object?> arguments,
Map<Symbol, Object?> namedArguments) {
if (arguments.length < 2) {
throw "Argument length must be 2.";
}
String? filename;
var filenameParsed = namedArguments[const Symbol('filename')];
if (filenameParsed != null) {
filename = filenameParsed as String;
}
return MultipartFile.fromString(
arguments.first as String, arguments[1] as String,
filename: filename);
}