type Animal = {
  age: number;
  type: 'dog',
};
const person = {
  name: 'zero',
  age: 28,
  sayName() {
    this;
    this.name;
  },

/*
this: {
  name: string;
  age: number;
  sayName(): void;
  sayAge(this: Animal): void;
}
*/

// (property) name: string
  sayAge(this: Animal) {
    this;
    this.type;
  }
};
// this: Animal
// (property) type: "dog"
person.sayAge.bind({ age: 3, type: 'dog' });