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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def projectSphereFilter(actor):
 """ Project a spherical-like object onto a plane. .. hint:: |projectsphere| |projectsphere.py|_ """

    poly = actor.polydata()
    psf = vtk.vtkProjectSphereFilter()
    psf.SetInputData(poly)
    psf.Update()
    a = Actor(psf.GetOutput())
    return a