private static Field doubleField(String name, ToDoubleFunctionThatThrows<WithGeometry> getter) {
    return new Field(name, Decls.Double, geom -> DoubleT.doubleOf(getter.applyAsDouble(geom)));
  }
Wrapper for a geometry that exposes utility functions to CEL expressions.
planetiler-custommap/src/main/java/com/onthegomap/planetiler/custommap/expression/stdlib/GeometryVal.java