[in] The ID of the item that contains the change unit that is associated with the clock vector to retrieve.
pbChangeUnitId
[in] The ID of the change unit that is associated with the clock vector to retrieve.
riid
[in] The IID of the object to retrieve. Must be IID_IEnumClockVector.
ppUnk
[out, riid_is(riid)] Returns an object that implements riid and that can enumerate the list of IClockVector objects that is associated with pbChangeUnitId.