@JsonIgnore
  @JsonProperty(ZOOM_KEY)
  public Double zoom() {
    if (center == null) {
      return null;
    }
    final double z = center.getZ();
    return Double.isNaN(z) ? null : z;
  }
Metadata associated with a tile archive.
<p>
The default (de-)serialization corresponds to the
<a href="https://github.com/mapbox/mbtiles-spec/blob/master/1.3/spec.md#metadata">mbtiles spec</a>. As such each
value is a string.
planetiler-core/src/main/java/com/onthegomap/planetiler/archive/TileArchiveMetadata.java