UIAccessibility.h

/*
 Returns the localized label(s) that should be provided by the user to refer to this element.
 Use this property when the accessibilityLabel is not appropriate for dictated or typed input.
 For example, an element that contains additional descriptive information in its accessibilityLabel can return a more concise label.
 The primary label should be first in the array, optionally followed by alternative labels in descending order of importance.
 If this property returns an empty or invalid value, the accessibilityLabel will be used instead.
 default == an empty array
 default on UIKit controls == an array with an appropriate label, if different from accessibilityLabel
 */
@available(iOS 13.0, *)
open var accessibilityUserInputLabels: [String]!