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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 add_axes_at_origin(self, loc=None):
 """ Add axes actor at the origin of a render window. Parameters loc : int, tuple, or list Index of the renderer to add the actor to. For example, ``loc=2`` or ``loc=(1, 1)``. When None, defaults to the active render window. Returns -------- marker_actor : vtk.vtkAxesActor vtkAxesActor actor """

        self._active_renderer_index = self.loc_to_index(loc)
        return self.renderers[self._active_renderer_index].add_axes_at_origin()