code: def test_ward2():
      myfield = basic_field_random()
      Lab, J1 = myfield.ward(5)
      Lab, J2 = myfield.ward(10)
      assert J1 > J2
  
imports: import numpy
  import numpy.random
  from numpy.testing import assert_array_equal
  from ..field import field_from_coo_matrix_and_data, field_from_graph_and_data
  from ..graph import wgraph_from_3d_grid
label_desc: Use image node_id 30 for calling a global function with example usage: test_ward2() without return types