input: Write a python function to parse a JSON string into a dictionary.
  assert parse_json('{"name": "John", "age": 30, "city": "New York"}') == {"name": "John", "age": 30, "city": "New York"}
  assert parse_json('{"name": "Alice", "age": 25, "city": "Los Angeles"}') == {"name": "Alice", "age": 25, "city": "Los Angeles"}
  assert parse_json('{"name": "Bob", "age": 22, "city": "Chicago"}') == {"name": "Bob", "age": 22, "city": "Chicago"}
output: import json
  
  def parse_json(json_string):
      return json.loads(json_string)