func (selector SetAreaSelector) PointZ(lat, lon, z float64) SetQueryBuilder {
	area := newCmd("POINT", floatString(lat), floatString(lon), floatString(z))
	return newSetQueryBuilder(selector.client, selector.key, selector.objectID, area)
}
PointZ - a point with Z coordinate.
This is application specific such as elevation, or a timestamp, etc.
package t38c
import geojson "github.com/paulmach/go.geojson"
type SetAreaSelector struct {
	client   tile38Client
	key      string
	objectID string
}
func newSetAreaSelector(client tile38Client, key, objectID string) SetAreaSelector {
	return SetAreaSelector{
		client:   client,
		key:      key,
		objectID: objectID,
	}
}
func (selector SetAreaSelector) Point(lat, lon float64) SetQueryBuilder {
	area := newCmd("POINT", floatString(lat), floatString(lon))
	return newSetQueryBuilder(selector.client, selector.key, selector.objectID, area)
}