@classmethod
    def _check_can_be_instantiated(cls):
        try:
            from bsddb import db
        except ImportError:
            try:
                from bsddb3 import db
            except __HOLE__:
                db = None
        if db is None:
            raise InvalidCacheException('no install of bsddb/bsddb3 found')
        del db
dataset/ETHPy150Open c-w/Gutenberg/gutenberg/acquire/metadata.py/SleepycatMetadataCache._check_can_be_instantiated