def METHOD_NAME(self, o):
    # Cutoff traversal by not having *ops in argument list of this
    # handler.  Traverse only the terminals under here the fastest
    # way we know of:
    for t in traverse_unique_terminals(o):
        if t._ufl_typecode_ == Argument._ufl_typecode_:
            raise ArityMismatch(f"Applying nonlinear operator {o._ufl_class_.__name__} to "
                                f"expression depending on form argument {t}.")
    return self._et