another OFieldCollection object that you are copying
Remarks
These methods construct a new OFieldCollection instance.
Constructing an OFieldCollection does not create any fields or OField objects.
The default constructor constructs an unopened OFieldCollection object. It cannot fail.
The copy constructor copies another OFieldCollection object. If that other OFieldCollection object is open - which means it is a handle on an implementation
FieldCollection object - the new OFieldCollection object becomes a handle to that same FieldCollection object. The copy
constructor can fail; check whether the new OFieldCollection is open after the constructor call.
There is no Open method for the OFieldCollection class. To get an open OFieldCollection, call one of the GetFields methods.