text: '''SQLAlchemy user and tweet models for our
  database.'''
  from flask_sqlalchemy import SQLAlchemy
  
  # creates a DB object (similar to our
  # cursor in regular sql.)
  DB = SQLAlchemy()
  
  # making a user table using sqlalchemy
  class User(DB.Model):
      # id column
      id = DB.Column(
          DB.BigInteger, primary_key = True
      )
      # name column
      username = DB.Column(DB.String,
      nullable = False)
  
      def __repr__(self):
          return "<User: {}>".format(
              self.username)
  
  class Tweet(DB.Model):
      '''Keeps track of tweets for every
      user.'''
      id = DB.Column(DB.BigInteger,
          primary_key = True)
      text = DB.Column(DB.Unicode(300))
      user_id = DB.Column(DB.BigInteger,
          DB.ForeignKey('user.id'),
          nullable = False)
      user = DB.relationship('User',
          backref = DB.backref('tweets',
          lazy = True))
      
      def __repr__(self):
          return "Tweet: {}".format(
              self.text
          )
  '''Run repl with FLASK_APP=app flask shell,
  this will allow us to interact with our DB
  as if it was in a production environment.'''
  