# File lib/hashie/mash.rb, line 266
    def method_missing(method_name, *args, &blk) # rubocop:disable Style/MethodMissing
      return self.[](method_name, &blk) if key?(method_name)
      name, suffix = method_name_and_suffix(method_name)
      case suffix
      when '='.freeze
        assign_property(name, args.first)
      when '?'.freeze
        !!self[name]
      when '!'.freeze
        initializing_reader(name)
      when '_'.freeze
        underbang_reader(name)
      else
        self[method_name]
      end
    end