create_fixtures

# File activerecord/lib/active_record/fixtures.rb, line 595
      def create_fixtures(fixtures_directories, fixture_set_names, class_names = {}, config = ActiveRecord::Base)
        fixture_set_names = Array(fixture_set_names).map(&:to_s)
        class_names.stringify_keys!

        connection_pool = config.connection_pool
        fixture_files_to_read = fixture_set_names.reject do |fs_name|
          fixture_is_cached?(connection_pool, fs_name)
        end

        if fixture_files_to_read.any?
          fixtures_map = read_and_insert(
            Array(fixtures_directories),
            fixture_files_to_read,
            class_names,
            connection_pool,
          )
          cache_fixtures(connection_pool, fixtures_map)
        end
        cached_fixtures(connection_pool, fixture_set_names)
      end