text: 'use strict';
  
  // refactor this function so there's one operation per step
  //  re-run the tests every time you make a change (even a tiny change!)
  //  practice using tests to pace your development
  
  /**
   * the worlds greatest mystery, will anyone ever know ?!
   * @param {any} a
   * @param {any} b
   * @returns {boolean}
   */
  const mystery = (a, b) => !+(!!a + (+b) % a);
  
  
  const _1_expect = false;
  const _1_actual = mystery('23', 23.0);
  console.assert(Object.is(_1_actual, _1_expect), 'Test 1');
  
  const _2_expect = true;
  const _2_actual = mystery('fdsa', 'fdsa');
  console.assert(Object.is(_2_actual, _2_expect), 'Test 2');
  
  const _3_expect = true;
  const _3_actual = mystery(undefined, null);
  console.assert(Object.is(_3_actual, _3_expect), 'Test 3');
  
  const _4_expect = false;
  const _4_actual = mystery(1000, 1e3);
  console.assert(Object.is(_4_actual, _4_expect), 'Test 4');
  
  const _5_expect = false;
  const _5_actual = mystery(true, 1);
  console.assert(Object.is(_5_actual, _5_expect), 'Test 5');
  
  const _6_expect = true;
  const _6_actual = mystery(undefined, NaN);
  console.assert(Object.is(_6_actual, _6_expect), 'Test 6');
  