Topic: testing multipleusers

hi,
In my application i am adding multipleusers through csv file.userid's which i have mentioned csv file will be saved in to database,when i select the csv file.now i want to do the unit testing for this.can i give multiple usernames  directly .like
  users = User.new(:username=>"abc@gmail.com",:username=>"sai@gmail.com")
  assert users.save
here passing assertions .but is this the correct method .plz tell me if not ,how to test

thanks in advance