def get_one(self, resource_type, requester_user):
        """
        List all the available permission types for a particular resource type.

        Handles requests:
            GET /rbac/permission_types/<resource type>
        """
        rbac_utils = get_rbac_backend().get_utils_class()
        rbac_utils.assert_user_is_admin(user_db=requester_user)

        all_permission_types = get_resource_permission_types_with_descriptions()
        permission_types = all_permission_types.get(resource_type, None)

        if permission_types is None:
            raise exc.HTTPNotFound("Invalid resource type: %s" % (resource_type))

        return permission_types

        List all the available permission types for a particular resource type.

        Handles requests:
            GET /rbac/permission_types/<resource type>
        
st2api/st2api/controllers/v1/rbac.py