src/vs/workbench/services/untitled/common/untitledTextEditorModel.ts/UntitledTextEditorModel/setDirty
class UntitledTextEditorModel:	private setDirty(dirty: boolean): void {
		if (this.dirty === dirty) {
			return;
		}

		this.dirty = dirty;
		this._onDidChangeDirty.fire();
	}