List<JobOffer> candidates = new ArrayList<JobOffer>(parked.size());
for (JobOffer j : parked.values())
if(j.canTake(p))
candidates.add(j);
MappingWorksheet ws = new MappingWorksheet(p, candidates);
Mapping m = loadBalancer.map(p.task, ws);
if (m == null)
// if we couldn't find the executor that fits,
// just leave it in the buildables list and
// check if we can execute other projects