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