Cannot declare conformance to 'NSObjectProtocol' in Swift

inheritance.swift

import AuthenticationServices
class Awesome: ASWebAuthenticationPresentationContextProviding { 
  // ERROR: Cannot declare conformance to 'NSObjectProtocol' in Swift
  ...
}

import Foundation
import AuthenticationServices
class Awesome: NSObject, ASWebAuthenticationPresentationContextProviding {
  ...
}

Initially found here while searching for the error message.

Presumably this is because ASWebAuthenticationPresentationContextProviding (Apple Swift Docs) inherits from NSObject? I'm not familiar with Objective-C, perhaps everything inherits from NSObject the way everything inherits from java.lang.Object in Java?

My understanding is that by extending NSObject we implement everything the NSObject-extended protocol requires, thus allowing us to satisfy the requirements for ASWebAuthenticationPresentationContextProviding implementation.