const Hashtable = require('hashtablejs');
 
function Point(x, y) {
  this.x = x;
  this.y = y;
}
 
function hashCode(point) {
  return `Point:${point.x},${point.y}`;
}
 
function equals(pointA, pointB) {
  return (pointA.x === pointB.x &&
          pointA.y === pointB.y);
}
 
const ht = new Hashtable(hashCode, equals);
 
console.log(ht.put(new Point(2,3), 'red')); // undefined
console.log(ht.has(new Point(2,3)); // true
console.log(ht.get(new Point(2,3)); // 'red'
console.log(ht.put(new Point(2,3), 'green')); // 'red'
console.log(ht.put(new Point(8,9), 'blue')); // undefined
console.log(ht.size()); // 2
console.log(ht.remove(new Point(8,9))); // 'blue'
console.log(ht.clear()); // true
console.log(ht.size()); // 0

Hashtable(hashCodeFn, equalsFn);
hashtable.has(key);
hashtable.put(key, value);
hashtable.get(key);
hashtable.remove(key);
hashtable.size();
hashtable.clear();
hashtable.entries();
hashtable.values();
hashtable.keys();
hashtable.each(fn);