invert_remove_unique_constraint

# File activerecord/lib/active_record/migration/command_recorder.rb, line 342
        def invert_remove_unique_constraint(args)
          _table, columns = args.dup.tap(&:extract_options!)

          raise ActiveRecord::IrreversibleMigration, "remove_unique_constraint is only reversible if given an column_name." if columns.blank?
          super
        end