ios – Swift expose the protocol to objc in protocol oriented programming

I’ve this code which works nicely:

public protocol PermissionProvider {
  static func authorizationStatus(for mediaType: AVMediaType) -> AVAuthorizationStatus
}

extension AVCaptureDevice: PermissionProvider {}

Now I want to reveal the protocol to Objc runtime:

@objc // added this attribute
public protocol PermissionProvider {
  static func authorizationStatus(for mediaType: AVMediaType) -> AVAuthorizationStatus
}

However I acquired an error saying:

AVFoundation.AVCaptureDevice:4:21: error: Goal-C methodology 'authorizationStatusForMediaType:' supplied by methodology 'authorizationStatus(for:)' doesn't match the requirement's selector ('authorizationStatusFor:')
    open class func authorizationStatus(for mediaType: AVMediaType) -> AVAuthorizationStatus

Why is it so?