"""Base classes for STIX 2.0 type definitions."""

from ..base import (
    _DomainObject, _Extension, _Observable, _RelationshipObject, _STIXBase,
)


class _STIXBase20(_STIXBase):
    pass


class _Observable(_Observable, _STIXBase20):

    def __init__(self, **kwargs):
        self._properties['extensions'].allow_custom = kwargs.get('allow_custom', False)
        super(_Observable, self).__init__(**kwargs)


class _Extension(_Extension, _STIXBase20):
    pass


class _DomainObject(_DomainObject, _STIXBase20):
    pass


class _RelationshipObject(_RelationshipObject, _STIXBase20):
    pass