private Collection<DfaRelation> getCallRelations(PsiCallExpression callExpression) {
    List<? extends MethodContract> contracts = JavaMethodContractUtil.getMethodCallContracts(callExpression);
    Set<DfaRelation> results = new LinkedHashSet<>();
    for (MethodContract contract : contracts) {
      for (ContractValue condition : contract.getConditions()) {
        DfaCondition rel = condition.fromCall(getFactory(), callExpression);
        ContainerUtil.addIfNotNull(results, ObjectUtils.tryCast(rel, DfaRelation.class));
      }
    }
    return results;
  }
private Collection<DfaRelation> getCallRelations(PsiCallExpression callExpression)