How to display NSText to NSWindow? - objective-c

Question

I have the following code:
#include <Cocoa/Cocoa.h>
NSColor *createColor(float r, float g, float b, float a) {
return [NSColor colorWithCalibratedRed:r green:g blue:b alpha:a];
}
NSRect createRect(float startX, float startY, float width, float height) {
return NSMakeRect(startX, startY, width, height);
}
int main() { #autoreleasepool {
NSWindow *window = [[NSWindow alloc] init];
window.title = #"Title";
window.subtitle = #"Subtitle";
NSText *label = [[NSText alloc] initWithFrame: createRect(10, 10, 20, 20)];
t.string = #"test";
[window setFrame:createRect(0, 0, 300, 300) display:YES animate:YES];
[window setBackgroundColor: createColor(0.5, 1, 0.1, 1)];
[window makeKeyAndOrderFront:nil];
while (1) {
NSEvent *event = [window nextEventMatchingMask:NSEventMaskAny];
}
}
}
Is there an simple way to display to NSWindow such as:
[window *command*: label];
I have looked at this post but it does not address my issue as it uses NSApplication rather than NSWindow. Also, I would prefer to use NSText instead of NSTextField.