run_prereq_migrations (Spec::Example::MigrationExampleGroup)

    # File lib/spec/example/migration_example_group.rb, line 34
          def run_prereq_migrations
            "running n-1 migrations"
            all_databases.each do |db|
              db.adapter.recreate_database
            end
            @@migrations.sort.each do |migration|
              break if migration.name.to_s == migration_name.to_s
              migration.perform_up
            end
          end