Given a new node, send it all the keys/values it should be storing,
        then add it to the routing table.

        @param node: A new node that just joined (or that we just found out
        about).

        Process:
        For each key in storage, get k closest nodes.  If newnode is closer
        than the furtherst in that list, and the node for this server
        is closer than the closest in that list, then store the key/value
        on the new node (per section 2.5 of the paper)

def welcome_if_new(self, node):
        """
        Given a new node, send it all the keys/values it should be storing,
        then add it to the routing table.

        @param node: A new node that just joined (or that we just found out
        about).

        Process:
        For each key in storage, get k closest nodes.  If newnode is closer
        than the furtherst in that list, and the node for this server
        is closer than the closest in that list, then store the key/value
        on the new node (per section 2.5 of the paper)
        """
        if not self.router.is_new_node(node):
            return

        log.info("never seen %s before, adding to router", node)
        for key, value in self.storage:
            keynode = Node(digest(key))
            neighbors = self.router.find_neighbors(keynode)
            if neighbors:
                last = neighbors[-1].distance_to(keynode)
                new_node_close = node.distance_to(keynode) < last
                first = neighbors[0].distance_to(keynode)
                this_closest = self.source_node.distance_to(keynode) < first
            if not neighbors or (new_node_close and this_closest):
                asyncio.ensure_future(self.call_store(node, key, value))
        self.router.add_contact(node)