code: def test_widget_sphere(uniform):
      p = pv.Plotter()
      func = lambda center: center  # Does nothing
      p.add_sphere_widget(callback=func, center=(0, 0, 0))
      p.close()
  
      # pass multiple centers
      nodes = np.array([[-1, -1, -1], [1, 1, 1]])
      p = pv.Plotter()
      func = lambda center, index: center  # Does nothing
      p.add_sphere_widget(callback=func, center=nodes)
      p.close()
  
imports: import numpy
  import pytest
  import vtk
  import pyvista
  from pyvista import examples
  from pyvista.core.errors import VTKVersionError
  from pyvista.plotting.affine_widget import DARK_YELLOW, get_angle, ray_plane_intersection
label_desc: Use image node_id 9 for calling a global function with example usage: test_widget_sphere(uniform) without return types