in server/src/jetbrains/buildServer/serverSide/priority/PriorityClassImpl.java [85:93]
public PriorityClass addBuildTypes(@NotNull final Collection<String> buildTypeIds) {
Set<String> newExternalIds = new HashSet<String>(myExternalIds);
for (String btId : buildTypeIds) {
SBuildType bt = myProjectManager.findBuildTypeById(btId);
if (bt != null)
newExternalIds.add(bt.getExternalId());
}
return new PriorityClassImpl(myProjectManager, myId, myName, myDescription, myPriority, newExternalIds);
}