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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 delaunay_3d(dataset, alpha=0, tol=0.001, offset=2.5):
 """Constructs a 3D Delaunay triangulation of the mesh. This helps smooth out a rugged mesh. Parameters alpha : float, optional Distance value to control output of this filter. For a non-zero alpha value, only verts, edges, faces, or tetra contained within the circumsphere (of radius alpha) will be output. Otherwise, only tetrahedra will be output. tol : float, optional tolerance to control discarding of closely spaced points. This tolerance is specified as a fraction of the diagonal length of the bounding box of the points. offset : float, optional multiplier to control the size of the initial, bounding Delaunay triangulation. """

        alg = vtk.vtkDelaunay3D()
        alg.SetInputData(dataset)
        alg.SetAlpha(alpha)
        alg.SetTolerance(tol)
        alg.SetOffset(offset)
        alg.Update()
        return _get_output(alg)