How can I pass null from react native to java when I develop a module

I’m developing a native module for Android in React Native. I have two method with the same name but I can’t use them in React Native because Java Script has not overloading directly. So I write a function which can get null as a paramater in React Native and try to handle it in Java.

React Native side:

    function a(arg=null){
       moduleName.b(arg)
    }

Java side:

public void wrapper(@Nullable Boolean arg, final Promise promise){
  if(arg == null){
    c()
  }else{
    c(arg)
  }
}

Then I have not problem when I pass true or false to function a but when I pass nothing to funtion a I get an error on my phone like that:

What is the problem?