def _is_stream(self, v):
        cached = None
        try:
            cached = self._stream_cache.get(v, None)
        except:
            pass
        if cached is not None:
            return cached
        if v and (isinstance(v, (file, StringIO)) or hasattr(v, 'fileno'))\
           or hasattr(v, 'write') or hasattr(v, 'read'):
            self.__add_to_stream_cache(v, True)
            return True
        try:
            from py._io.capture import EncodedFile
            from py._io.capture import DontReadFromInput
            if isinstance(v, (EncodedFile, DontReadFromInput)):
                self.__add_to_stream_cache(v, True)
                return True
        except:
            pass
        self.__add_to_stream_cache(v, False)
        return False
Create a new DagNode...Read node from a given dataPacket type.
dataset/ETHPy150Open thasso/pyjip/jip/options.py/Option._is_stream--crossover with--dataset/ETHPy150Open andrew-gardner/dependsworkflow/depends/depends_node.py/readNodeClassFactory