Payload

Represents the notification level. The currently supported value is 0, which indicates that the notification should be spoken aloud.

The ID of the device that triggered the event, which may be different than the device transmitting the notification.

Descriptive air quality level value. Valid qualities are defined in AirQualityLevel.

The location where air quality is measured.

A textual representation of this instance, suitable for debugging.

Calling this property directly is discouraged. Instead, convert an instance of any type to a string by using the String(reflecting:) initializer. This initializer works with any type, and uses the custom debugDescription property for types that conform to CustomDebugStringConvertible:

struct Point: CustomDebugStringConvertible {
    let x: Int, y: Int

    var debugDescription: String {
        return "(\(x), \(y))"
    }
}

let p = Point(x: 21, y: 30)
let s = String(reflecting: p)
print(s)
// Prints "(21, 30)"

The conversion of p to a string in the assignment to s uses the Point type’s debugDescription property.