old_contents: from flask import Flask
  from flask import request
  from firebase import firebase
  
  app = Flask(__name__)
  
  @app.route('/')
  def hello_world():
      return 'Hello, World!'
  
  @app.route('/createuser')
  def create_user():
      username = request.args.get('username')
      password = request.args.get('password')
  
new_contents: from flask import Flask
  from flask import request
  import pyrebase
  
  app = Flask(__name__)
  
  config = {
    "apiKey": "AIzaSyBXZpwPptJjUJddDl6Q0DpG_3k7mGDdHk8",
    "authDomain": "my-first-project-fea9c.firebaseapp.com",
    "databaseURL": "https://my-first-project-fea9c.firebaseio.com/",
    "storageBucket": "my-first-project-fea9c.appspot.com"
  }
  
  firebase = pyrebase.initialize_app(config)
  
  @app.route('/')
  def hello_world():
      return 'Hello, World!'
  
  @app.route('/createuser')
  def create_user():
      username = request.headers.get('email')
      password = request.headers.get('password')
      auth = firebase.auth()
      auth.create_user_with_email_and_password(username, password)
  
  @app.route('/login')
  def login():
      username = request.headers.get('email')
      password = request.headers.get('password')
      auth = firebase.auth()
      auth.sign_in_with_email_and_password(username, password)
subject: implement create user + login