initializer

# File railties/lib/rails/initializable.rb, line 130
      def initializer(name, opts = {}, &blk)
        raise ArgumentError, "A block must be passed when defining an initializer" unless blk
        opts[:after] ||= initializers.last&.name unless initializers.has?(opts[:before])
        initializers << Initializer.new(
          name, nil, before: opts[:before], after: opts[:after], group: opts[:group], &blk
        )
      end