Get a key if the network has it.

        Returns:
            :class:`None` if not found, the value otherwise.

async def get(self, key):
        """
        Get a key if the network has it.

        Returns:
            :class:`None` if not found, the value otherwise.
        """
        log.info("Looking up key %s", key)
        dkey = digest(key)
        # if this node has it, return it
        if self.storage.get(dkey) is not None:
            return self.storage.get(dkey)
        node = Node(dkey)
        nearest = self.protocol.router.find_neighbors(node)
        if not nearest:
            log.warning("There are no known neighbors to get key %s", key)
            return None
        spider = ValueSpiderCrawl(self.protocol, node, nearest,
                                  self.ksize, self.alpha)
        return await spider.find()