code: def _urls(self):
          
          urlpatterns = self._get_default_urlpatterns()
          self._autodiscover()
  
          # Discover each dashboard's panels.
          for dash in self._registry.values():
              dash._autodiscover()
  
          # Load the plugin-based panel configuration
          self._load_panel_customization()
  
          # Allow for override modules
          if self._conf.get("customization_module", None):
              customization_module = self._conf["customization_module"]
              bits = customization_module.split('.')
              mod_name = bits.pop()
              package = '.'.join(bits)
              mod = import_module(package)
              try:
                  before_import_registry = copy.copy(self._registry)
                  import_module('%s.%s' % (package, mod_name))
              except Exception:
                  self._registry = before_import_registry
                  if module_has_submodule(mod, mod_name):
                      raise
  
          # Compile the dynamic urlconf.
          for dash in self._registry.values():
              urlpatterns.append(url(r'^%s/' % dash.slug,
                                     _wrapped_include(dash._decorated_urls)))
  
          # Return the three arguments to django.conf.urls.include
          return urlpatterns, self.namespace, self.slug
docs: Constructs the URLconf for Horizon from registered Dashboards.