# File lib/rgen/model_builder/builder_context.rb, line 147
    def extensionContainer(package)
      return @extensionContainer[package] if @extensionContainer[package]
      container = ExtensionContainer.new(@builderContext)
      extensionModule = moduleForPackage(package)
      container.extend(extensionModule) if extensionModule
      @extensionContainer[package] = container
    end