public OsmNode getStartNode(final long id) {
        // initialize the start-node
        final OsmNode n = new OsmNode(id);
        n.setHollow();
        nodesMap.put(n);
        if (!obtainNonHollowNode(n)) {
            return null;
        }
        expandHollowLinkTargets(n);
        return n;
    }
get a node for the given id with all link-targets also non-hollow
<p>
It is required that an instance of the start-node does not yet
exist, not even a hollow instance, so getStartNode should only
be called once right after resetting the cache

@param id the id of the node to load
@return the fully expanded node for id, or null if it was not found
main/src/main/java/cgeo/geocaching/brouter/mapaccess/NodesCache.java