PetscSF Object: 2 MPI processes
  type not yet set
  PetscSFSetGraph() has not been called yet
PetscSF Object: 2 MPI processes
  type: basic
  [0] Number of roots=0, leaves=0, remote ranks=0
  [1] Number of roots=0, leaves=0, remote ranks=0
  MultiSF sort=rank-order
PetscSF Object: 2 MPI processes
  type: basic
  PetscSFSetGraph() has not been called yet
PetscSF Object: 2 MPI processes
  type: basic
  [0] Number of roots=0, leaves=0, remote ranks=0
  [1] Number of roots=0, leaves=0, remote ranks=0
  MultiSF sort=rank-order