public List<ApproverResponse> listByCondition(ApproverPageRequest request) {
        Preconditions.expectNotNull(request.getPageNum(), "page num cannot be null");
        Preconditions.expectNotNull(request.getPageSize(), "page size cannot be null");

        Map<String, Object> requestMap = JsonUtils.OBJECT_MAPPER.convertValue(request,
                new TypeReference<Map<String, Object>>() {
                });
        requestMap.entrySet().removeIf(entry -> Objects.isNull(entry.getValue()));
        Response<PageResult<ApproverResponse>> response = ClientUtils.executeHttpCall(
                workflowApproverApi.listByCondition(requestMap));
        ClientUtils.assertRespSuccess(response);

        return response.getData().getList();
    }
List the workflow approvers according to the query request

@param request page query request
@return approver list
inlong-manager/manager-client/src/main/java/org/apache/inlong/manager/client/api/inner/client/WorkflowApproverClient.java