Check if an object is not empty in Typescript

Question

I have an interface like the following:

interface Cat {
  age? : number
  name? : string
}

with the following scenario:

function getAge(cat: Cat) {
  // ...
}

const catWithAge = getAge({}) // this is ok according the Cat interface

What I would like to do is the function getAge not to accept an empty object.

I would like to have at least one key passed in the object (doesn't matter which one).

What should I change in order to achieve this?