This callback method is invoked by the %New method to
provide notification that a new instance of an object is being created.
If this method returns an error then the object will not be created.
It is passed the arguments provided in the %New call.
When customizing this method, override the arguments with whatever variables and types you expect to receive from %New().
For example, if you're going to call %New, passing 2 arguments, %OnNew's signature could be:
Method %OnNew(dob as %Date = "", name as %Name = "") as %Status
If instead of returning a %Status code this returns an oref and this oref is a subclass of the current
class then this oref will be the one returned to the caller of %New method.
