In a movie review system, the users can write reviews of movies and other users can upvote (helpful) or downvote (unhelpful) those reviews.
If a user named John writes a review on the movie. Another person named Alice can upvote or downvote that review. And, One user can cast one and only one vote on a specific review.
I am creating the REST API based on the endpoints and other information. I am using the node.js environment running in the Express server.
