def METHOD_NAME(self):
    font = TTFont()
    font.importXML(os.path.join(DATA_DIR, "_h_h_e_a_recalc_empty.ttx"))
    hhea = font["hhea"]
    hhea.recalc(font)
    self.assertEqual(hhea.advanceWidthMax, 600)
    self.assertEqual(hhea.minLeftSideBearing, 0)
    self.assertEqual(hhea.minRightSideBearing, 0)
    self.assertEqual(hhea.xMaxExtent, 0)