input: Write a function to parse a json-formatted string into a dictionary in Python using the json module. Return the parsed dictionary.
  assert parse_json_string('{"name": "John","age": 30,"address": {"city": "New York","state": "NY"}}')=={"name": "John","age": 30,"address": {"city": "New York","state": "NY"}}
  assert parse_json_string('{"fruit": "apple","color": "red","quantity": 5}')=={"fruit": "apple","color": "red","quantity": 5}
  assert parse_json_string('[]')==[]
  assert parse_json_string('"Hello World"')=="Hello World"
output: import json
  
  def parse_json_string(json_str):
      return json.loads(json_str)