def _read_header(self):
        self._fh.seek(0)
        buf = self._fh.read(4*2)
        fc, dc = struct.unpack("<II", buf)
        return fc, dc
Set the visible state on the underlying control.
dataset/ETHPy150Open dongying/dear/dear/spectrum/_base.py/SpectrogramFile._read_header--crossover with--dataset/ETHPy150Open ContinuumIO/ashiba/enaml/enaml/qt/qt_action.py/QtAction.set_visible