/*D
   MPI_Win_get_group - Get the MPI Group of the window object

Synopsis:
.vb
int MPI_Win_get_group(MPI_Win win, MPI_Group *group)
.ve

Input Parameters:
. win - window object (handle)

Output Parameters:
. group - group of processes which share access to the window (handle)

Notes:
The group is a duplicate of the group from the communicator used to
create the MPI window, and should be freed with 'MPI_Group_free' when
it is no longer needed.  This group can be used to form the group of
neighbors for the routines 'MPI_Win_post' and 'MPI_Win_start'.

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_ARG
.N MPI_ERR_WIN
.N MPI_ERR_OTHER

D*/

