code: public List<ExpressionRootInner> listExpressionTraces(String resourceGroupName, String workflowName, String runName, String actionName) {
          return listExpressionTracesWithServiceResponseAsync(resourceGroupName, workflowName, runName, actionName).toBlocking().single().body();
      }
docs: Lists a workflow run expression trace.
  
  @param resourceGroupName The resource group name.
  @param workflowName The workflow name.
  @param runName The workflow run name.
  @param actionName The workflow action name.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws CloudException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the List&lt;ExpressionRootInner&gt; object if successful.