interface Name {
  first: string
  second: string
}

var name: Name
name = {
  first: "John",
  second: "Doe",
}

name = {
  // Error : `second` is missing
  first: "John",
}
name = {
  // Error : `second` is the wrong type
  first: "John",
  second: 1337,
}

interface Point {
  x: number
  y: number
}

class MyPoint implements Point {
  x: number
  y: number // Same as Point
}