if (punctType === 'PERIOD' && !(/\.$/u).test(preceedingSubfield.value)) { // eslint-disable-line functional/no-conditional-statements
        const nextValue = `${preceedingSubfield.value}.`;
        debug(`Updated subfield ${preceedingSubfield.code} from '${preceedingSubfield.value}' to '${nextValue}'`);
        preceedingSubfield.value = nextValue; // eslint-disable-line functional/immutable-data
      }