[CONNECT C++] Viewport::GetRotMatrix()

In DgnViewport.h there is this note by GetRotMatrix():

//! Get the Rotation Matrix for this Viewport. The concept of a Viewport's Rotation Matrix is somewhat limiting since it does not
//! support perspective transformations. This method is provided for compatibility with previous MicroStation API only.
//! @see the Coordinate Coordinate Query and Conversion functions and #GetRootToViewMap

So what should be done to grab a view's Rotation instead?