@classmethod
def parse_args(cls, subparsers):
    """Add Cloud Object Storage arguments to command line parser."""
    cos_oo_parser = subparsers.add_parser('cos', description=cls.__doc__)
    cos_oo_parser.add_argument('-e', '--endpoint-url', help=
        'endpoint URL of the S3 storage')
    cos_oo_parser.add_argument('-s', '--instance-id', help=
        'service instance id')
    cos_oo_parser.add_argument('-u', '--access-key', help=
        'acccess key id of HMAC credentials')
    cos_oo_parser.add_argument('-p', '--secret-key', help=
        'secret access key of HMAC credentials')
    cos_oo_parser.add_argument('local_path', nargs='?', default=None, help=
        'path in the local file system of the file to be uploaded')
    cos_oo_parser.add_argument('bucket', help='target s3 bucket')
    cos_oo_parser.add_argument('remote_path', help=
        """path on Cloud Object Storage where the file
                                  will be stored"""
        )
