Context manager that changes the current translation language for
    all code inside the following block.

    Can e.g. be used inside tasks like this::

        from celery import task
        from djcelery.common import respect_language

        @task
        def my_task(language=None):
            with respect_language(language):
                pass

def respect_language(language):
    """Context manager that changes the current translation language for
    all code inside the following block.

    Can e.g. be used inside tasks like this::

        from celery import task
        from djcelery.common import respect_language

        @task
        def my_task(language=None):
            with respect_language(language):
                pass
    """
    if language:
        prev = translation.get_language()
        translation.activate(language)
        try:
            yield
        finally:
            translation.activate(prev)
    else:
        yield