/**
* Gets the changes in the dependency between the given build and this build.
*/
public Map<AbstractProject,DependencyChange> getDependencyChanges(AbstractBuild from) {
if (from==null) return Collections.emptyMap(); // make it easy to call this from views
FingerprintAction n = this.getAction(FingerprintAction.class);
FingerprintAction o = from.getAction(FingerprintAction.class);
if (n==null || o==null) return Collections.emptyMap();
Map<AbstractProject,Integer> ndep = n.getDependencies();
Map<AbstractProject,Integer> odep = o.getDependencies();
Map<AbstractProject,DependencyChange> r = new HashMap<AbstractProject,DependencyChange>();
for (Map.Entry<AbstractProject,Integer> entry : odep.entrySet()) {
AbstractProject p = entry.getKey();