input: Write a function to get recommendations for a given user.
  assert get_recommendations(user) == expected_recommendations
  assert get_recommendations(another_user) == another_expected_recommendations
output: def get_recommendations(user):
      # Simulating a recommendation system with a dummy implementation
      user_recommendations = {
          'user1': ['item1', 'item2', 'item3'],
          'user2': ['item4', 'item5', 'item6'],
      }
      return user_recommendations.get(user, [])