class_docstr: Shape
  
  Searchlight shape which is contained in a cube sized
  (2*rad+1,2*rad+1,2*rad+1)
  
  Attributes
  ----------
  
  mask_ : a 3D boolean numpy array of size (2*rad+1,2*rad+1,2*rad+1)
          which is set to True within the boundaries of the desired shape
  
  Parameters
  ----------
  
  rad: radius, in voxels, of the sphere inscribed in the
       searchlight cube, not counting the center voxel
class_docstr_tok: ["Shape","Searchlight","shape","which","is","contained","in","a","cube","sized","(","2","*","rad+1,2","*","rad+1,2","*","rad+1",")","Attributes","--","--","--","--","--","mask_",":","a","3D","boolean","numpy","array","of","size","(","2","*","rad+1,2","*","rad+1,2","*","rad+1",")","which","is","set","to","True","within","the","boundaries","of","the","desired","shape","Parameters","--","--","--","--","--","rad",":","radius",",","in","voxels",",","of","the","sphere","inscribed","in","the","searchlight","cube",",","not","counting","the","center","voxel"]
code: def __init__(self, rad):
      self.rad = rad
  
imports: from multiprocessing import Pool
  import numpy
  from mpi4py import MPI
  from scipy.spatial.distance import cityblock, euclidean
  from ..utils.utils import usable_cpu_count
label_desc: Use image node_id 1 to create a new Shape object  with example: obj = Shape(rad)