def download(self, bucket_name, object_name, filename=None):
client = self.get_conn()<EOL>bucket = client.get_bucket(bucket_name)<EOL>blob = bucket.blob(blob_name=object_name)<EOL>if filename:<EOL><INDENT>blob.download_to_filename(filename)<EOL>self.log.info('<STR_LIT>', filename)<EOL><DEDENT>return blob.download_as_string()<EOL>
Get a file from Google Cloud Storage.

:param bucket_name: The bucket to fetch from.
:type bucket_name: str
:param object_name: The object to fetch.
:type object_name: str
:param filename: If set, a local file path where the file should be written to.
:type filename: str