'Set up the manager and load all plugins.
:type   app:        UniverseApplication
:param  app:        the application (and its configuration) using this manager
:type   base_url:   string
:param  base_url:   url to prefix all plugin urls with
:type   template_cache_dir: string
:param  template_cache_dir: filesytem path to the directory where cached
templates are kept'

def __init__(self, app, base_url='', template_cache_dir=None, **kwargs):

    self.base_url = (base_url or self.DEFAULT_BASE_URL)
    if (not self.base_url):
        raise PluginManagerException('base_url    or    DEFAULT_BASE_URL    required')
    self.template_cache_dir = template_cache_dir
    self.additional_template_paths = []
    super(PageServingPluginManager, self).__init__(app, **kwargs)
