def __init__(self, types, **kwargs):
        instances = []
        for t in types:
            inheritance_comparator = issubclass if isinstance(t, type) else isinstance
            if not inheritance_comparator(t, Column):
                raise ValidationError("%s is not a column class" % (t,))
            if t.db_type is None:
                raise ValidationError("%s is an abstract type" % (t,))
            inst = t() if isinstance(t, type) else t
            if isinstance(t, BaseCollectionColumn):
                inst._freeze_db_type()
            instances.append(inst)

        self.types = instances
        super(BaseCollectionColumn, self).__init__(**kwargs)
Get the public key of the certificate
dataset/ETHPy150Open datastax/python-driver/cassandra/cqlengine/columns.py/BaseCollectionColumn.__init__--crossover with--dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/pyopenssl/OpenSSL/crypto.py/NetscapeSPKI.get_pubkey