APIDiagram Editor APIHistory manager APIHistory manager methodsundo()On this pageundo() Description Reverts the last action in the Diagram EditorUsageundo(first?: boolean): void;Parameters first - (optional) true to revert all the history of changes Exampleconst editor = new dhx.DiagramEditor("editor_container", { type: "default"});// ...editor.history.undo();Change log: Added in v4.1