This method sets the new "last data update time" for the complex table.
By default, the last update time will be "now"; however, if your underlying data source has a concept of a last update time, you can pass that on to the Agentry Server by calling this method from the constructor, build(), or dataIterator() to set it.
Note that calling this method does not affect the return value of getClientLastDataUpdateTime(); the two values are maintained separately.