newRoot.js

//ROOT Tree (rotated to RIGHT):
{
  this.value = 15;
  this.left = null;
  this.right = null;
  this.parent = {node: BST(10), side: 'right'};
}
//root.height() => 0;
//root.balanceFactor() => 0;

//PIVOT Tree (rotated to ROOT):
{
  this.value = 10;
  this.left = BST(7);
  this.right = BST(15);
  this.parent = {node: BST(20), side: 'left'};
}
//pivot.height() => 1;
//pivot.balanceFactor() => 0;

//PARENT Tree (of root):
{
  this.value = 20;
  this.left = BST(10);
  this.right = BST(25);
  this.parent = {node: null, side: ''}
}
//parent.height() => 2;
//parent.balanceFactor() => 1;