text: const mongoose = require('mongoose')
  const Schema = mongoose.Schema
  
  const userSchema = new Schema(
    {
      username: {
        type: String,
        unique: true,
        required: true
      },
      password: {
        type: String,
        required: true
      }
    },
    {
      timestamps: {
        createdAt: 'created_at',
        updatedAt: 'updated_at'
      }
    }
  )
  
  module.exports = mongoose.model('User', userSchema)
  