docs: public String calculateLabelUnit(final CoordinateReferenceSystem mapCrs) {
          String unit;
          if (this.labelProjection != null) {
              unit = this.labelCRS.getCoordinateSystem().getAxis(0).getUnit().toString();
          } else {
              unit = mapCrs.getCoordinateSystem().getAxis(0).getUnit().toString();
          }
  
          return unit;
      }