Call operator for objc.ObjCBlock<objc.NSProgress Function(ffi.Pointer<ffi.Void>)>.
objc.ObjCBlock<objc.NSProgress Function(ffi.Pointer<ffi.Void>)>
Available on ObjCBlock<NSProgress Function(Pointer<Void>)>, provided by the ObjCBlock_NSProgress_ffiVoid_CallExtension extension