Which type of value in the object as parameter of function. Why do not have the compilation errors?

I have gotten the next bunch of code.

const func: ( newState: { newState: number }) => void = ({ newState: newState }) => {
    console.log(newState);
}

For me, particularly interesting is the ({ newState: newState }) how is it work?
Why can I write newState: newState in this situation, and no compilation errors?

>Solution :

 const func: ( labeledParameter: { newState: number }) => void = ({ newState: test }) => {
    console.log(test);
}

func({newState: 12});

It’s because the first newState is a label put on the parameters give to the function -> i renamed it labeledParameter in my sample

the object

{ newState: newState }

is an object with a property newState and as value a number

to call the function you should use

func({newState: 12});