each time a new virtual method is added and so, at least for the compilers
using a common C++ object model, the calling program is compatible with any
renderer which has the age greater or equal to its age. This verification is
each time a new virtual method is added and so, at least for the compilers
using a common C++ object model, the calling program is compatible with any
renderer which has the age greater or equal to its age. This verification is