Solution Review: Sets

'use strict';
class BoundedSet extends Set {
  constructor(capacity, initialValues) {
    super();
    this.capacity = capacity;
    if(initialValues.length <= capacity) {
      initialValues.forEach(value => this.add(value));
    }
  }
  add(value) {
    if(this.has(value)) return;
    if(this.size < this.capacity) {
      super.add(value);
    } else {
      throw new Error(`exceeded capacity of ${this.capacity} elements`);
    }
  }
}
const set = new BoundedSet(5, ['Apple', 'Banana', 'Grape', 'Mango']);
set.add('Orange');
set.add('Apple');
try {
  set.add('Tangerine');
} catch(ex) {
  console.log(ex.message); //exceeded capacity of 5 elements
}
set.delete('Grape');
set.add('Peach');
console.log(set.size); //5
const set2 = new BoundedSet(2, ['Apple', 'Banana', 'Grape']);
console.log(set2.size); //0
console.log(set2.capacity); //capacity