code: def cube_sfn(data, msk, myrad, bcast_var):
      if np.all(msk) and np.any(msk):
          return 1.0
      return None
  
file_path: brainiak/tests/searchlight/test_searchlight.py
imports: from collections import namedtuple
  import numpy
  from mpi4py import MPI
  import conftest
  from brainiak.searchlight.searchlight import Searchlight
  from brainiak.searchlight.searchlight import Diamond, Ball
label_desc: Use image node_id 1 for calling a global function with example usage: cube_sfn(data, msk, myrad, bcast_var) and returns: None, int