code: @Service
      public List<String> getRunningWorkflows(String workflowName, Integer version,
                                              Long startTime, Long endTime) {
          if (Optional.ofNullable(startTime).orElse(0l) != 0 && Optional.ofNullable(endTime).orElse(0l) != 0) {
              return workflowExecutor.getWorkflows(workflowName, version, startTime, endTime);
          } else {
              return workflowExecutor.getRunningWorkflowIds(workflowName);
          }
      }
docs: Retrieves all the running workflows.
  
  @param workflowName Name of the workflow.
  @param version      Version of the workflow.
  @param startTime    Starttime of the workflow.
  @param endTime      EndTime of the workflow
  @return a list of workflow Ids.