在插件中用代码生成多个单据，如何控制在一个事务中完成

FormMetadata formMetadata = ServiceFactory.GetMetaDataService(Context).Load(this.Context, "单据一", true) as FormMetadata;
DynamicObject dynamicObject = formMetadata.BusinessInfo.GetDynamicObjectType().CreateInstance() as DynamicObject;
//设置字段值
......
FormMetadata formMetadata2 = ServiceFactory.GetMetaDataService(Context).Load(this.Context, "单据二", true) as FormMetadata;
DynamicObject dynamicObject2 = formMetadata2.BusinessInfo.GetDynamicObjectType().CreateInstance() as DynamicObject;
//设置字段值
......
如何在一个事务中调用保存方法？