code: def add_permissions(self, grp_name, resource, permissions):
          
          self.service.add_permissions(
              grp_name, resource, permissions,
              self.url_prefix, self.auth, self.session, self.session_send_opts)
docs: Add additional permissions for the group associated with the given resource.
  
          Args:
              grp_name (string): Name of group.
              resource (intern.resource.boss.BossResource): Identifies which data model object to operate on.
              permissions (list): List of permissions to add to the given resource.
  
          Raises:
              requests.HTTPError on failure.