How can I stop faker gem from failing username uniqueness validation in ruby on rails?
namespace :db do
      namespace :development do
        desc "Create user records in the development database."
        task :populate => :environment do
          require 'faker'

          1000.times do

            User.create!(
            :username => Faker::Internet.user_name,
            :email => Faker::Internet.email,
            :password => "greatpasswordhuh"
    )


          end
        end
      end
    end

1000.times do |n|
  username = Faker::Internet.user_name
  username = "#{username}_#{n}"
  ...
end

namespace :db do
        desc "Create user records in the development database."
        task :populate => :environment do
          require 'faker'

          100.times do |n|
            username = "#{Faker::Name.first_name}#{n}"
            User.create!(
              :username => username,
              :email => Faker::Internet.email,
              :password => "greatpasswordhuh"
            )

        end
      end
    end