input: Write a python function to reformat a JSON string with indentation.
  assert reformat_json('{"name":"Jason","age":42,"favorite_food":"Lasagna"}') == '{\n    "name": "Jason",\n    "age": 42,\n    "favorite_food": "Lasagna"\n}'
  assert reformat_json('{"city":"New York","population":8398748}') == '{\n    "city": "New York",\n    "population": 8398748\n}'
output: def reformat_json(json_string):
      import json
      parsed_json = json.loads(json_string)
      return json.dumps(parsed_json, indent=4)