code: func (t *Transformer) Transform(e *pdk.Entity) error {
  	latitude, err := e.F64(t.LatPath...)
  	if err != nil {
  		return errors.Wrap(err, "getting latidude")
  	}
  	longitude, err := e.F64(t.LonPath...)
  	if err != nil {
  		return errors.Wrap(err, "getting longitude")
  	}
  	hsh := geoHash(float64(latitude), float64(longitude), t.Precision)
  	err = e.SetString(hsh, t.ResultPath...)
  	return errors.Wrap(err, "setting result")
  }
docs: // Transform hashes the latitude and longitude at the given paths and sets the
  // resulting string at the result path on the Entity.