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