invert_add_index

# File activerecord/lib/active_record/migration/command_recorder.rb, line 162
        def invert_add_index(args)
          table, columns, options = *args
          options ||= {}

          index_name = options[:name]
          options_hash = index_name ? { name: index_name } : { column: columns }

          [:remove_index, [table, options_hash]]
        end