'Load history data from a previous operation.'

def load_and_validate_existing(self, storage):

    data = storage.get_document_history(self.locale, self.slug)
    if (data and (len(data[u'revisions']) >= self.revisions)):
        requested_revisions = data[u'revisions'][:self.revisions]
        requested_revisions.reverse()
        return (True, requested_revisions)
    else:
        return (False, [])
