I'm trying to build a function that accepts an object of any shape, but I want to be sure that the object always have a specific property of a given type.

```
function ofInterest(param: any){
   // do some computation using param's p property
   ... = param.p
}

```

That way calling function `ofInterest` with a parameter which does not have the desired property results in a type check error:

```
const param = {q: '', r: 0}

// this should be an error cause param does not have a property 'p'
ofInterest(param)

```

How can I declare `ofInterest`'s param?