let cgImage = try QRCode.build
.text("https://github.com/dagronf/QRCode")
.generate.image(dimension: 600)
QRCodeDocument* doc = [QRCodeDocument new];
[doc setUtf8String: @"https://github.com/dagronf/QRCode"];
NSError* error = NULL;
CGImageRef image = [doc cgImageWithDimension:600 error:&error];