When the output of remesh_keeping_periodicity_for_fem() was changed from pv.UnstructuredGrid only to either pv.UnstructuredGrid or BoxMesh, the example did not take this update into account and tried to call save() method in a BoxMesh, which does not exist (but does in a pv.UnstructuredGrid).
This PR fixes the given remesh example.
When the output of
remesh_keeping_periodicity_for_fem()was changed frompv.UnstructuredGridonly to eitherpv.UnstructuredGridorBoxMesh, the example did not take this update into account and tried to callsave()method in aBoxMesh, which does not exist (but does in apv.UnstructuredGrid).