def get_overlay(self, subject, type='rois', **kwargs):
        try:
            group = self.h5['subjects'][subject]
            if type == "rois":
                tf = tempfile.NamedTemporaryFile()
                tf.write(group['rois'][0])
                tf.seek(0)
                return tf
        except (KeyError, __HOLE__):
            raise IOError('Overlay not found in package')

        raise TypeError('Unknown overlay type')
dataset/ETHPy150Open gallantlab/pycortex/cortex/dataset/__init__.py/Dataset.get_overlay