def from_dict(cls, d):
        """Unserialize a TLSExtensionSignature from a dict.

        Initializes the suitable subclass if exists, otherwise initializes
        a TLSExtensionSignature proper instance.
        """
        d = d.copy()
        ext_type = TLSExtensionType[d.pop("type")]
        if ext_type in cls.registry:
            return cls.registry[ext_type].from_dict(d)
        else:
            return TLSExtensionSignature(
                ext_type=ext_type,
                length=d.pop("length", None)
            )
Unserialize a TLSExtensionSignature from a dict.

        Initializes the suitable subclass if exists, otherwise initializes
        a TLSExtensionSignature proper instance.
        
tests/signature.py