def __init__(self, path_mapping=None):
    try:
        import ceph
        warnings.warn('Ceph is deprecate in favor of Petrel.')
    except ImportError:
        raise ImportError('Please install ceph to enable CephBackend.')
    self._client = ceph.S3Client()
    assert (isinstance(path_mapping, dict) or (path_mapping is None))
    self.path_mapping = path_mapping
def __init__(self, path_mapping=None):
    try:
        import ceph
        warnings.warn('Ceph is deprecate in favor of Petrel.')
    except ImportError:
        raise ImportError('Please install ceph to enable CephBackend.')
    self._client = ceph.S3Client()
    assert (isinstance(path_mapping, dict) or (path_mapping is None))
    self.path_mapping = path_mapping