docs: def has_perm(self, perm):
          """
          Checks if key has the given django's auth Permission
          """
          if '.' in perm:
              app_label, codename = perm.split('.')
              permissions = self.permissions.filter(
                  content_type__app_label = app_label, 
                  codename = codename)
              groups = self.groups.filter(
                  permissions__content_type__app_label = app_label,
                  permissions__codename = codename )
          else:
              permissions = self.permissions.filter(codename = perm)
              groups = self.groups.filter(permissions__codename = perm)
          return permissions.exists() or groups.exists()