Provide potentially streaming download from S3 using gof3r
        or the AWS CLI.

        Selects the correct endpoint for non us-east support:
            http://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region

        In eu-central-1 gof3r does not support new AWS signatures,
        so we fall back to the standard AWS commandline interface:
            https://github.com/rlmcpherson/s3gof3r/issues/45

def _download_cl(cls, filename):
        """Provide potentially streaming download from S3 using gof3r
        or the AWS CLI.

        Selects the correct endpoint for non us-east support:
            http://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region

        In eu-central-1 gof3r does not support new AWS signatures,
        so we fall back to the standard AWS commandline interface:
            https://github.com/rlmcpherson/s3gof3r/issues/45
        """
        file_info = cls.parse_remote(filename)
        region = cls.get_region(filename)
        if region in REGIONS_NEWPERMS["s3"]:
            return cls._cl_aws_cli(file_info, region)
        else:
            return cls._cl_gof3r(file_info, region)