code: public void updateWorkflowDefs(List<WorkflowDef> workflowDefs) {
          Preconditions.checkNotNull(workflowDefs, "Workflow defs list cannot be null");
          put("metadata/workflow", null, workflowDefs);
      }
docs: Updates a list of existing workflow definitions
  
  @param workflowDefs List of workflow definitions to be updated