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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 get_bounds(self):
 """Get the mesh bounds Returns ------- bounds : list A list of tuples of mesh bounds. """

        if self._vertices_indexed_by_faces is not None:
            v = self._vertices_indexed_by_faces
        elif self._vertices is not None:
            v = self._vertices
        else:
            return None
        bounds = [(v[:, ax].min(), v[:, ax].max()) for ax in range(v.shape[1])]
        return bounds