call method
Implementation
void call(ffi.Pointer<ffi.Void> arg0) => ref.pointer.ref.invoke
.cast<ffi.NativeFunction<ffi.Void Function(ffi.Pointer<objc.ObjCBlockImpl> block, ffi.Pointer<ffi.Void> arg0)>>()
.asFunction<void Function(ffi.Pointer<objc.ObjCBlockImpl>, ffi.Pointer<ffi.Void>)>()(ref.pointer, arg0);