text: 'use strict'
  
  /*
   * Create a `sub` function that takes 2 numbers as arguments and substract them
   *
   * @notions Primitive and Operators, Functions
   */
  
  // Your code :
  function sub(number, number2) {
      return number - number2
  }
  
  //* Begin of tests
  const assert = require('assert')
  const rand = Math.random()
  
  assert.strictEqual(typeof sub, 'function')
  assert.strictEqual(sub.length, 2)
  assert.strictEqual(sub(2, 2), 0)
  assert.strictEqual(sub(-2, 2), -4)
  assert.strictEqual(sub(rand, rand), rand - rand)
  // End of tests */
  