module Roda::RodaPlugins::Base::ClassMethods

def plugin(plugin, *args, &block)

Roda.plugin :csrf
Roda.plugin PluginModule

which will be required and then used.
which is used directly, or a symbol represented a registered plugin
Load a new plugin into the current class. A plugin can be a module 
def plugin(plugin, *args, &block)
  if plugin.is_a?(Symbol)
    plugin = RodaPlugins.load_plugin(plugin)
  end
  if plugin.respond_to?(:load_dependencies)
    plugin.load_dependencies(self, *args, &block)
  end
  if defined?(plugin::InstanceMethods)
    include(plugin::InstanceMethods)
  end
  if defined?(plugin::ClassMethods)
    extend(plugin::ClassMethods)
  end
  if defined?(plugin::RequestMethods)
    self::RodaRequest.send(:include, plugin::RequestMethods)
  end
  if defined?(plugin::RequestClassMethods)
    self::RodaRequest.extend(plugin::RequestClassMethods)
  end
  if defined?(plugin::ResponseMethods)
    self::RodaResponse.send(:include, plugin::ResponseMethods)
  end
  if defined?(plugin::ResponseClassMethods)
    self::RodaResponse.extend(plugin::ResponseClassMethods)
  end
  
  if plugin.respond_to?(:configure)
    plugin.configure(self, *args, &block)
  end
end