text: const rot47 = require('./rot47');
  
  describe('rot47', () => {
      const lower = 'abcdefghijklmnopqrstuvwxyz';
      const rotatedLower = '23456789:;<=>?@ABCDEFGHIJK';
      it('rotates correctly', () => {
          const actual = rot47(lower);
          const expected = rotatedLower;
          expect(actual).toEqual(expected);
      });
      it('double rotation nullifies', () => {
          const actual = rot47(rot47(lower));
          const expected = lower;
          expect(actual).toEqual(expected);
      });
  });
  