code: def test_distance_multi():
      import mahotas._morph
  
      np.random.seed(20)
      binim = np.random.random((12, 18)) > 0.1
      f = (binim * 0 + 26 * 27).astype(np.float_)
      Bc = np.ones((3, 3), bool)
      mahotas._morph.distance_multi(f, binim, Bc)
      f2 = mahotas.distance(binim)
      assert np.all(f == f2)
  
imports: import mahotas
  import numpy
  from mahotas.morph import get_structuring_elem, subm, tophat_open, tophat_close
  import pytest
label_desc: Use image node_id 15 for calling a global function with example usage: test_distance_multi() without return types