input: Write a python function to classify food items into "healthy" and "unhealthy" based on their protein, fat, and carbs content.
  assert classify([{"protein":20,"fat":20,"carbs":30},{"protein":10,"fat":45,"carbs":30}]) == {"healthy": [{"protein":20,"fat":20,"carbs":30}], "unhealthy": [{"protein":10,"fat":45,"carbs":30}]}
  assert classify([{"protein":15,"fat":10,"carbs":40},{"protein":8,"fat":25,"carbs":50}]) == {"healthy": [{"protein":15,"fat":10,"carbs":40}], "unhealthy": [{"protein":8,"fat":25,"carbs":50}]}
  assert classify([{"protein":12,"fat":18,"carbs":45},{"protein":11,"fat":22,"carbs":55}]) == {"healthy": [{"protein":12,"fat":18,"carbs":45}], "unhealthy": [{"protein":11,"fat":22,"carbs":55}]}
output: def classify(food_items):
      result = {"healthy": [], "unhealthy": []}
      for item in food_items:
          if item["fat"] < 25:
              result["healthy"].append(item)
          else:
              result["unhealthy"].append(item)
      return result