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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 _validate_image_rank(self, img_array):
 """ Images must be either 2D or 3D. """

        if img_array.ndim == 1 or img_array.ndim > 3:
            msg = "{0}D imagery is not allowed.".format(img_array.ndim)
            raise IOError(msg)