invert_add_index

# File activerecord/lib/active_record/migration/command_recorder.rb, line 81
      def invert_add_index(args)
        table, columns, options = *args
        index_name = options.try(:[], :name)
        options_hash =  index_name ? {:name => index_name} : {:column => columns}
        [:remove_index, [table, options_hash]]
      end