text: const missingInUnsorted = require('.');
  
  const arr = [2, 5, 1, 4, 9, 6, 3, 7];
  const lowerBound = 1;
  const upperBound = 9;
  
  const missing = missingInUnsorted(arr, lowerBound, upperBound);
  
  test('missingInUnsorted([2, 5, 1, 4, 9, 6, 3, 7], 1, 9) should be 8', () => {
    expect(missing).toEqual(8);
  });
  