code: def next(self, increment=1):
      incr = _array("i", [increment])
      nval = _array("i", [0])
      self.win.Lock(0)
      self.win.Get_accumulate(
          [incr, 1, MPI.INT], [nval, 1, MPI.INT], 0, op=MPI.SUM
      )
      self.win.Unlock(0)
      return nval[0]
  
file_path: mpi4py/demo/nxtval/nxtval-mpi3.py
imports: from mpi4py import MPI
  from array import array
  import struct
label_desc: Use image node_id 3 for calling the Counter obj's underlying member method code with example usage: obj.next(increment) and returns: nval