def allowed_classes(self):
data = clips.data.DataObject(self._env)<EOL>lib.EnvSlotAllowedClasses(<EOL>self._env, self._cls, self._name, data.byref)<EOL>if isinstance(data.value, list):<EOL><INDENT>for klass in classes(self._env, data.value):<EOL><INDENT>yield klass<EOL><DEDENT><DEDENT>
Iterate over the allowed classes for this slot.

        The Python equivalent of the CLIPS slot-allowed-classes function.