text: /***
   * @summary
   * 
   * MongoDB is has its own Schemas. Hence,
   * postedBy: { type: Schema.Types.ObjectId, ref: 'User' },
   * 
   * Which allows us to specify Schema.Types.ObjectId, and use ObjectId 
   * as opposed to getting Username associated with the post. 
   *  
   */
  const mongoose = require('mongoose');
  
  const Schema = mongoose.Schema;
  
  const PostSchema = new Schema({
      content: { type: String, trim: true },
      postedBy: { type: Schema.Types.ObjectId, ref: 'User' },
      pinned: { type: Boolean },
      likes: [{ type: Schema.Types.ObjectId, ref: 'User' }],
      retweetUsers: [{ type: Schema.Types.ObjectId, ref: 'User' }],
      retweetData: { type: Schema.Types.ObjectId, ref: 'Post' },
      replyTo: { type: Schema.Types.ObjectId, ref: 'Post' }
  }, { timestamps: true });
  
  var Post = mongoose.model('Post', PostSchema);
  module.exports = Post;