@Override
    public Instant asTimestamp() {
      try {
        return Instant.parse(value);
      } catch (DateTimeParseException e) {
        Long value = asLong();
        if (value != null) {
          return Instant.ofEpochMilli(value);
        }
        return null;
      }
    }
Returns a new list where each element of this list has been expanded to the list of elements returned by
{@code mapper}.
<p>
Individual items are treated as a list containing just that item.
planetiler-core/src/main/java/com/onthegomap/planetiler/reader/Struct.java