input: Write a python function to create, update, delete, and list blog posts using Flask and Flask-RESTful.
  assert create_blog_post('1', {'title': 'First Post', 'content': 'This is the first post'}) == {'title': 'First Post', 'content': 'This is the first post'}
  assert update_blog_post('1', {'title': 'Updated Post', 'content': 'This is the updated content'}) == {'title': 'Updated Post', 'content': 'This is the updated content'}
  assert delete_blog_post('1') == 'Post deleted'
  assert list_blog_posts() == {}
output: from flask import Flask, request
  from flask_restful import Resource, Api
  
  app = Flask(__name__)
  api = Api(app)
  
  posts = {}
  
  class BlogPost(Resource):
      def get(self, post_id):
          return posts.get(post_id, 'Post not found'), 200 if post_id in posts else 404
  
      def post(self, post_id):
          posts[post_id] = request.json
          return posts[post_id], 201
  
      def put(self, post_id):
          if post_id in posts:
              posts[post_id] = request.json
              return posts[post_id], 200
          return 'Post not found', 404
  
      def delete(self, post_id):
          if post_id in posts:
              del posts[post_id]
              return 'Post deleted', 200
          return 'Post not found', 404
  
  class BlogPostList(Resource):
      def get(self):
          return posts, 200
  
  api.add_resource(BlogPost, '/post/<string:post_id>')
  api.add_resource(BlogPostList, '/posts')
  
  def create_blog_post(post_id, data):
      with app.test_client() as client:
          response = client.post(f'/post/{post_id}', json=data)
          return response.json
  
  def update_blog_post(post_id, data):
      with app.test_client() as client:
          response = client.put(f'/post/{post_id}', json=data)
          return response.json
  
  def delete_blog_post(post_id):
      with app.test_client() as client:
          response = client.delete(f'/post/{post_id}')
          return response.get_data(as_text=True)
  
  def list_blog_posts():
      with app.test_client() as client:
          response = client.get('/posts')
          return response.json