PyVTKObject: own the classname memory
PyVTKObject: own the classname memory

In Python3, we take the actual object and construct a new bytes() object
from it. We then take a pointer to its data and decref the bytes object.
If the garbage collector runs between the decref and the use of the
classname variable further down, it is a use-after-free.

sumedhasingla/VTK,SimVascular/VTK,SimVascular/VTK,sumedhasingla/VTK,sumedhasingla/VTK,keithroe/vtkoptix,SimVascular/VTK,sumedhasingla/VTK,sumedhasingla/VTK,SimVascular/VTK,sumedhasingla/VTK,SimVascular/VTK,sumedhasingla/VTK,keithroe/vtkoptix,SimVascular/VTK,SimVascular/VTK,sumedhasingla/VTK,keithroe/vtkoptix,keithroe/vtkoptix,keithroe/vtkoptix,keithroe/vtkoptix,SimVascular/VTK,keithroe/vtkoptix,keithroe/vtkoptix