The examples https://github.com/enthought/chaco/tree/master/examples/demo/vtk and https://github.com/enthought/chaco/blob/master/examples/demo/vtk_example.py use the now non-existent vtk backend in `enable` so they should be removed.
The examples https://github.com/enthought/chaco/tree/master/examples/demo/vtk and https://github.com/enthought/chaco/blob/master/examples/demo/vtk_example.py use the now non-existent vtk backend in
enableso they should be removed.