Create a class diagram for the following requirements using PlantUML
syntax. Show all the relationships between the classes. For instance,
if there is a property List<User>, display the aggregation between
the User class and the class containing the property. Present the
output as a code block.

Requirements:

"""
Movie Database App

Find your next movie or create your watchlist with this App. 
It include reviews, rating, actors and anything you need to know
about the movie.

This application will help users find their next movie to watch by
showing helpful stats. Resource needed for the project is movie api,
examples include Imdb, MovieDB etc.

User Stories
 User can see all the latest movie on the front page
 User scroll down to see all other movies according to release date
 User can click on any of the movie to go to their own separate page
 User can then see all about the movie ratings, about, actors
   present on each separate movie page
Bonus features
 User can create an account
 User can create their own watch list
 User can review movies
Useful links and resources
MovieDB Api
"""

@startuml
class User {
  +username: String
  +password: String
  +createAccount()
  +createWatchList()
  +reviewMovie()
}

class Movie {
  +id: String
  +title: String
  +releaseDate: Date
  +rating: Float
  +about: String
  +actors: List<Actor>
  +getDetails()
}

class Actor {
  +name: String
  +getDetails()
}

class Review {
  +userId: String
  +movieId: String
  +rating: Float
  +comment: String
  +submitReview()
}

class WatchList {
  +userId: String
  +movies: List<Movie>
  +addMovie()
  +removeMovie()
}

class MovieAPI {
  +sourceName: String
  +getLatestMovies()
  +getMovieDetails()
}

User "1" -- "0..*" Review : writes >
User "1" -- "1" WatchList : owns >
Review "0..*" -- "1" Movie : reviews >
WatchList "1" -- "0..*" Movie : contains >
Movie "1" -- "0..*" Actor : has >
MovieAPI ..> Movie : provides >
@enduml

Based on the class diagram, write a backend implementation
using Python and Flask

from flask import Flask, request
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy.orm import relationship

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////tmp/test.db'
db = SQLAlchemy(app)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    password = db.Column(db.String(120), nullable=False)
    reviews = relationship("Review", backref="user")
    watchlist = relationship("WatchList", uselist=False, back_populates="user")

class Movie(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(120), nullable=False)
    release_date = db.Column(db.DateTime, nullable=False)
    rating = db.Column(db.Float, nullable=False)
    about = db.Column(db.String(500), nullable=False)
    actors = db.Column(db.String(500), nullable=False)
    reviews = relationship("Review", backref="movie")
    watchlists = relationship("WatchList", back_populates="movies")

class Review(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
    movie_id = db.Column(db.Integer, db.ForeignKey('movie.id'))
    rating = db.Column(db.Float, nullable=False)
    comment = db.Column(db.String(500), nullable=True)

class WatchList(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
    movie_id = db.Column(db.Integer, db.ForeignKey('movie.id'))
    user = relationship("User", back_populates="watchlist")
    movies = relationship("Movie", back_populates="watchlists")

@app.route('/user', methods=['POST'])
def create_user():
    data = request.get_json()
    new_user = User(username=data['username'], password=data['password'])
    db.session.add(new_user)
    db.session.commit()
    return {"message": "User created successfully."}, 201

@app.route('/movie', methods=['POST'])
def add_movie():
    data = request.get_json()
    new_movie = Movie(title=data['title'], release_date=data['release_date'], rating=data['rating'], about=data['about'], actors=data['actors'])
    db.session.add(new_movie)
    db.session.commit()
    return {"message": "Movie added successfully."}, 201

@app.route('/review', methods=['POST'])
def add_review():
    data = request.get_json()
    new_review = Review(user_id=data['user_id'], movie_id=data['movie_id'], rating=data['rating'], comment=data['comment'])
    db.session.add(new_review)
    db.session.commit()
    return {"message": "Review added successfully."}, 201

@app.route('/watchlist', methods=['POST'])
def create_watchlist():
    data = request.get_json()
    new_watchlist = WatchList(user_id=data['user_id'], movie_id=data['movie_id'])
    db.session.add(new_watchlist)
    db.session.commit()
    return {"message": "Watchlist created successfully."}, 201

if __name__ == "__main__":
    db.create_all()
    app.run(debug=True)

Create a class diagram for the following code using PlantUML
syntax. Show all the relationships between the classes.

Code:
"""
<paste your code here>
"""