Function extraHeaders

src/ui-react-dom/common/index.tsx:80–88

(
  extraCells: (ExtraRowCell | ExtraValueCell)[] = [],
  after: 0 | 1 = 0,
)

  (after ? '>' : '<') + index;

export const extraHeaders = (
  extraCells: (ExtraRowCell | ExtraValueCell)[] = [],
  after: 0 | 1 = 0,
) =>
  arrayMap(extraCells, ({label}, index) => (
    <th className={EXTRA} key={extraKey(index, after)}>
      {label}
    </th>
  ));