src/vs/workbench/contrib/notebook/common/notebookEditorModel.ts/ComplexNotebookEditorModel/setDirty
class ComplexNotebookEditorModel:	setDirty(newState: boolean) {
		if (this._dirty !== newState) {
			this._dirty = newState;
			this._onDidChangeDirty.fire();
		}
	}