constructor(initialCapacity = 16, loadFactor = 0.75) {
    this.buckets = new Array(initialCapacity);
    this.loadFactor = loadFactor;
    this.size = 0;
    this.collisions = 0;
    this.keysArrayWrapper = [];
  }
Initialize array that holds the values. Default is size 16
@param {number} initialCapacity initial size of the array
@param {number} loadFactor if set, the Map will automatically rehash when the load factor threshold is met