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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _decode_next_layer(self, dict_, length=None):
 """Decode next layer protocol. Positional arguments: dict_ -- dict, info buffer proto -- str, next layer protocol name length -- int, valid (not padding) length Returns: * dict -- current protocol with packet extracted """

        seek_cur = self._file.tell()
        try:
            next_ = self._import_next_layer(self._prot, length)
        except Exception:
            dict_['error'] = traceback.format_exc(limit=1).strip().split(os.linesep)[-1]
            self._file.seek(seek_cur, os.SEEK_SET)
            next_ = beholder(self._import_next_layer)(self, self._prot, length, error=True)
        info, chain = next_.info, next_.protochain

        # make next layer protocol name
        layer = next_.alias.lower()
        # proto = next_.__class__.__name__

        # write info and protocol chain into dict
        self._next = next_
        self._protos = chain
        dict_[layer] = info
        dict_['protocols'] = self._protos.chain
        return dict_