Time-dependent solution: Animation in FEnics 2019

1

How to store time-dependent solution in .pvd formate?
How to visualize it in ParaView?

2

See for instance: https://bitbucket.org/fenics-project/dolfin/raw/74a6ac2095059ea6582fe4ea11686c1c723e14f5/python/demo/documented/navier-stokes/demo_navier-stokes.py