code: def mybor(a, b, dt):
      assert dt == MPI.BYTE
      assert len(a) == len(b)
      for i in range(len(a)):
          b[i] = a[i] | b[i]
  
imports: from mpi4py import MPI
  import mpiunittest
label_desc: Use image node_id 5 for calling a global function with example usage: mybor(a, b, dt) without return types