text: 'use strict';
  
  /*
   * Create a `keepFirst` function that takes a string as parameter
   * and return the string only keeping the 2 first characters
   *
   * Create a `keepLast` function that takes a string as parameter
   * and return the string only keeping the 2 last characters
   *
   * Create a `keepFirstLast` function that takes a string as parameter
   * and only keep 2 characters from the third character
   *
   */
  
  // Your code:
  const keepFirst = (str) => str.substring(0, 2)
  const keepLast = (str) => str.substring(str.length - 2)
  const keepFirstLast = (str) => str.substring(2, 2 + 2)
  //* Begin of tests
  const assert = require('assert');
  assert.strictEqual(typeof keepFirst, 'function');
  assert.strictEqual(typeof keepLast, 'function');
  assert.strictEqual(typeof keepFirstLast, 'function');
  assert.strictEqual(keepFirst.length, 1);
  assert.strictEqual(keepLast.length, 1);
  assert.strictEqual(keepFirstLast.length, 1);
  assert.strictEqual(keepFirst('Hello'), 'He');
  assert.strictEqual(keepLast('Hello'), 'lo');
  assert.strictEqual(keepFirstLast('Hello'), 'll');
  //assert.fail('You must write your own tests');
  // End of tests */
  