type A = {
    prop1: string,
    prop2: {
        prop3: string
    }
}

function isA(obj:any): boolean {
    // What should be here?
}

{
 prop1: "Hello",
 prop2: {
    prop3: "World"
 }
}

{
     prop1: "Hello",
     prop2: {
        prop3: "World"
     },
     moreProps: "I don't care about"
}

{
     foo: "Hello",
     bar: {
        prop3: "World"
     }
}