def _fetch_data(self):
        """Converts inputspec to files"""
        if (self.inputs.surface_target == "fsnative" or
                self.inputs.volume_target != "MNI152NLin2009cAsym"):
            # subject space is not support yet
            raise NotImplementedError

        annotation_files = sorted(glob(os.path.join(self.inputs.subjects_dir,
                                                    self.inputs.surface_target,
                                                    'label',
                                                    '*h.aparc.annot')))
        if not annotation_files:
            raise IOError("Freesurfer annotations for %s not found in %s" % (
                          self.inputs.surface_target, self.inputs.subjects_dir))

        label_file = str(get_template(
            'MNI152NLin2009cAsym', resolution=2, desc='DKT31', suffix='dseg'))
        return annotation_files, label_file
Converts inputspec to files