How to use the mnelab.model.LabelsNotFoundError function in mnelab

def import_bads(self, fname):
        """Import bad channels info from a CSV file."""
        with open(fname) as f:
            bads = f.read().replace(" ", "").strip().split(",")
            unknown = set(bads) - set(self.current["data"].info["ch_names"])
            if unknown:
                msg = ("The following imported channel labels are not " +
                       "present in the data: " + ",".join(unknown))
                raise LabelsNotFoundError(msg)
            else:
                self.current["data"].info["bads"] = bads

def import_file(self, f, text, ffilter="*"):
        """Import file."""
        fname = QFileDialog.getOpenFileName(self, text, filter=ffilter)[0]
        if fname:
            try:
                f(fname)
            except LabelsNotFoundError as e:
                QMessageBox.critical(self, "Channel labels not found", str(e))
            except InvalidAnnotationsError as e:
                QMessageBox.critical(self, "Invalid annotations", str(e))