def get(self, id, pk='id', deleted=False):
        try:
            if pk == 'id':
                id = int(id)
            if deleted:
                spec = {pk: id}
            else:
                spec = {pk: id, 'data': {'$exists': 1}}
            fields = {'_id': 0}
            row = self.db.docs.find_one(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return Document(**row)
        raise NotFoundError('%s %s not found' % (pk, id))
def call_vision_api(image_filename, api_keys):
    api_key = api_keys['microsoft']
    post_url = "https://api.projectoxford.ai/vision/v1.0/analyze?visualFeatures=Categories,Tags,Description,Faces,ImageType,Color,Adult&subscription-key=" + api_key

    image_data = open(image_filename, 'rb').read()
    result = requests.post(post_url, data=image_data, headers={'Content-Type': 'application/octet-stream'})
    result.raise_for_status()

    return result.text