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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 boolean_add(self, mesh, inplace=False):
 """ Add a mesh to the current mesh. Does not attempt to "join" the meshes. Parameters mesh : vtki.PolyData The mesh to add. inplace : bool, optional Updates mesh in-place while returning nothing. Returns ------- joinedmesh : vtki.PolyData Initial mesh and the new mesh when inplace=False. """

        vtkappend = vtk.vtkAppendPolyData()
        vtkappend.AddInputData(self)
        vtkappend.AddInputData(mesh)
        vtkappend.Update()

        mesh = _get_output(vtkappend)
        if inplace:
            self.overwrite(mesh)
        else:
            return mesh