There was a problem studying the typescript.
How to specify a declared interface as the type of map?
exmaple code)
interface User {
  id: number;
  name: string;
  age: number;
  house: {
    id: number;
    address: string;
    ...,
    ...
  }
  ...,
  ...
}
const userMap = new Map<User>();  // a different motion than expected... 
    