private static RoutingTableSpec getRoutingTable(RoutingSpec routing, String protocol) {
        for (int i = 0, len = routing.getNumTables(); i < len; ++i) {
            RoutingTableSpec table = routing.getTable(i);
            if (protocol.equals(table.getProtocol())) {
                return table;
            }
        }
        return null;
    }
Returns the routing table from the given routing spec that belongs to the named protocol.

@param routing  the routing whose tables to search through
@param protocol the name of the protocol whose table to return
@return the routing table found, or null
config-model/src/main/java/com/yahoo/vespa/model/routing/Routing.java