private Object2IntMap<PsiTypeVariable> calculateDegree() {
    Object2IntMap<PsiTypeVariable> result=new Object2IntOpenHashMap<>();
    for (Constraint constr : myConstraints) {
      PsiTypeVarCollector collector = new PsiTypeVarCollector();
      setDegree(collector.getSet(constr.getRight()), result);
    }
    return result;
  }
private Object2IntMap<PsiTypeVariable> calculateDegree()