Multiple PythonViews not supported

Reported here: https://discourse.paraview.org/t/what-to-pass-as-view-for-python-view-call-render-function/9784

From the post:

multiple PythonView instances will all use the same render function, even if the code in each view’s Script window is completely different. Whichever render function was modified last is the one used to render all PythonViews. Thought that using custom render functions would solve this issue.