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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 async def _set_annotations(entity_tag, annotations, connection):
 """Set annotations on the specified entity. :param annotations map[string]string: the annotations as key/value pairs. """

    # TODO: ensure annotations is dict with only string keys
    # and values.
    log.debug('Updating annotations on %s', entity_tag)
    facade = client.AnnotationsFacade.from_connection(connection)
    args = client.EntityAnnotations(
        entity=entity_tag,
        annotations=annotations,
    )
    return await facade.Set([args])