code: function updateWorkflow(workflow, meta, callback) {
              if (typeof (meta) === 'function') {
                  callback = meta;
                  meta = {};
              }
  
              if (workflows[workflow.uuid]) {
                  if (_wfNames().indexOf(workflow.name) !== -1 &&
                      workflows[workflow.uuid].name !== workflow.name) {
                      return callback(new e.BackendInvalidArgumentError(
                        'Workflow.name must be unique. A workflow with name "' +
                        workflow.name + '" already exists'));
                  } else {
                      workflows[workflow.uuid] = clone(workflow);
                      return callback(null, workflow);
                  }
              } else {
                  return callback(new e.BackendResourceNotFoundError(
                    'Workflow does not exist. Cannot Update.'));
              }
          }
docs: workflow - update workflow object. meta - Any additional information to pass to the backend which is not workflow properties callback - f(err, workflow)