private static void updateContract(@NotNull PsiMethod method) {
    PsiAnnotation annotation = JavaMethodContractUtil.findContractAnnotation(method);
    if (annotation == null || annotation.getOwner() != method.getModifierList()) return;
    String text = AnnotationUtil.getStringAttributeValue(annotation, null);
    if (text == null || text.trim().isEmpty()) return;
    List<StandardMethodContract> contracts;
    try {
      contracts = StandardMethodContract.parseContract(text);
    }
    catch (StandardMethodContract.ParseException ignore) {
      return;
    }
    List<StandardMethodContract> newContracts = ContainerUtil.map(contracts, contract -> {
      ContractReturnValue value = contract.getReturnValue();
      return value instanceof ContractReturnValue.BooleanReturnValue ?
             contract.withReturnValue(((ContractReturnValue.BooleanReturnValue)value).negate()) :
             contract;
    });
    if (newContracts.equals(contracts)) return;
    PsiAnnotation newAnnotation = JavaMethodContractUtil.updateContract(annotation, newContracts);
    if (newAnnotation != null) {
      annotation.replace(newAnnotation);
    }
  }
private static void updateContract(@NotNull PsiMethod method)