text: const mongoose = require('mongoose');
  const AutoIncrement = require('mongoose-sequence')(mongoose);
  
  const userSchema = new mongoose.Schema({
  	user_id: {
  		type: Number,
  		index: true
  	},
  	user_name: {
  		type: String,
  		unique: true,
  		required: true,
  		index: true
  	},
  	first_name: String,
  	last_name: String
  }, {collection: 'user'});
  userSchema.plugin(AutoIncrement, {id: 'user.user_id', inc_field: 'user_id', collection_name: 'sequences'});
  
  module.exports = mongoose.model('User', userSchema);
  