text: 'use strict';
  
  const ImplicitTreap = require('../implicit-treap.js');
  
  const treap = new ImplicitTreap().fromArray([
    1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
  ]);
  
  treap.rangeUpdate(3, 13, node => {
    const temp = node.left;
    node.left = node.right;
    node.right = temp;
  });
  
  console.log([...treap]);
  