Setup for Sphinx extension.

    :param app: Sphinx application context.

def setup(app):
    """
    Setup for Sphinx extension.

    :param app: Sphinx application context.
    """
    app.info('adding remote-code-block directive...', nonl=True)
    app.add_directive('remote-code-block', RemoteCodeBlock)
    app.info(' done')
    return {
        'version': __version__,
        'parallel_read_safe': True,
        'parallel_write_safe': True,
        }