@classmethod<EOL><INDENT>def _inv_cls(cls):<DEDENT>
if cls._fwdm_cls is cls._invm_cls:<EOL><INDENT>return cls<EOL><DEDENT>if not getattr(cls, '<STR_LIT>', None):<EOL><INDENT>class _Inv(cls):<EOL><INDENT>_fwdm_cls = cls._invm_cls<EOL>_invm_cls = cls._fwdm_cls<EOL>_inv_cls_ = cls<EOL><DEDENT>_Inv.__name__ = cls.__name__ + '<STR_LIT>'<EOL>cls._inv_cls_ = _Inv<EOL><DEDENT>return cls._inv_cls_<EOL>
The inverse of this bidict type, i.e. one with *_fwdm_cls* and *_invm_cls* swapped.