JS: using object from parent class

class Class1 {
  
  constructor() {
   this.things = [];
   this.testValue = "one two three";
  }
  
  doThings() {
  
        for(let i = 0; i < 10; i++) {
            this.things[i] = "test "+i;
        }
    
    console.log("Class 1 doThings(): ", this.things);
  
  }
  
  getContent() {
      console.log("getContent Class1: ", this.things);
  }
  
}

class Class2 extends Class1 {

  constructor(elmnt){
    super();
  }
  
  getContent() {
      console.log("Class 2 getContent(): ", this.things);
  }
  
  getValue() {
    
    console.log("Value: ", this.testValue)
    
  }

}

let handle1 = new Class1();
let handle2 = new Class2();

handle1.getContent(); // empty because this.things() did not run
handle1.doThings(); // create things...
handle1.getContent(); // this shows the things

handle2.getContent(); // this is empty even is doThings() is called before to produce things...

handle2.getValue();