PetscSF Object: sfA 1 MPI process
  type: basic
  [0] Number of roots=4, leaves=4, remote ranks=1
  [0] 2 <- (0,0)
  [0] 3 <- (0,1)
  [0] 4 <- (0,2)
  [0] 5 <- (0,3)
  MultiSF sort=rank-order
PetscSF Object: sfB 1 MPI process
  type: basic
  [0] Number of roots=8, leaves=2, remote ranks=1
  [0] 2 <- (0,3)
  [0] 3 <- (0,2)
  MultiSF sort=rank-order
BcastB(BcastA)
A: root data
0: 0 1 2 3
A: leaf data (all)
0: -1 -1 0 1 2 3 -1 -1
B: leaf data (all)
0: -1 -1 1 0 -1 -1
PetscSF Object: sfBA 1 MPI process
  type: basic
  [0] Number of roots=4, leaves=2, remote ranks=1
  [0] 2 <- (0,1)
  [0] 3 <- (0,0)
  MultiSF sort=rank-order
BcastBA
BA: root data
0: 0 1 2 3
BA: leaf data (all)
0: -1 -1 1 0 -1 -1
PetscSF Object: sfAm 1 MPI process
  type: basic
  [0] Number of roots=6, leaves=4, remote ranks=1
  [0] 0 <- (0,2)
  [0] 1 <- (0,3)
  [0] 2 <- (0,4)
  [0] 3 <- (0,5)
  MultiSF sort=rank-order
PetscSF Object: sfAAm 1 MPI process
  type: basic
  [0] Number of roots=4, leaves=4, remote ranks=1
  [0] 0 <- (0,0)
  [0] 1 <- (0,1)
  [0] 2 <- (0,2)
  [0] 3 <- (0,3)
  MultiSF sort=rank-order
PetscSF Object: sfBm 1 MPI process
  type: basic
  [0] Number of roots=4, leaves=2, remote ranks=1
  [0] 2 <- (0,3)
  [0] 3 <- (0,2)
  MultiSF sort=rank-order
PetscSF Object: sfBBm 1 MPI process
  type: basic
  [0] Number of roots=8, leaves=2, remote ranks=1
  [0] 2 <- (0,2)
  [0] 3 <- (0,3)
  MultiSF sort=rank-order