code: private boolean canRun(String flowName, String flowGroup, boolean allowConcurrentExecution) {
      if (allowConcurrentExecution) {
        return true;
      } else {
        return !flowStatusGenerator.isFlowRunning(flowName, flowGroup);
      }
    }
docs: Check if the flow instance is allowed to run.
  @param flowName
  @param flowGroup
  @param allowConcurrentExecution
  @return true if the {@link FlowSpec} allows concurrent executions or if no other instance of the flow is currently RUNNING.