public static String headerRow() {
    return String.join(
      String.valueOf(SCHEMA.getColumnSeparator()),
      SCHEMA.getColumnNames()
    ) + new String(SCHEMA.getLineSeparator());
  }
Returns the header row for the output TSV file.
planetiler-core/src/main/java/com/onthegomap/planetiler/util/TileSizeStats.java