@classmethod
def from_existing(cls, klass):
    """Build a new `_CivisBackend` from an existing one."""
    return cls(setup_cmd=klass.setup_cmd, from_template_id=klass.
        from_template_id, max_submit_retries=klass.max_submit_retries,
        client=klass.client, remote_backend=klass.remote_backend, **klass.
        executor_kwargs)
