@Override
  public Val get(Val index) {
    if (!(index instanceof StringT)) {
      return noSuchOverload(this, "get", index);
    }
    String fieldName = (String) index.value();
    try {
      var field = FIELDS.get(fieldName);
      return field.getter.apply(geometry);
    } catch (Exception err) {
      return Err.newErr(err, "Error getting %s", fieldName);
    }
  }
Wrapper for a geometry that exposes utility functions to CEL expressions.
planetiler-custommap/src/main/java/com/onthegomap/planetiler/custommap/expression/stdlib/GeometryVal.java