code: public boolean open() throws RasterWritingFailureException {
          boolean ok;
          if (mapPath != null) {
              ok = writer.open(mapPath);
          } else if (locationPath != null && mapsetName != null && mapName != null) {
              ok = writer.open(mapName, locationPath, mapsetName);
          } else {
              return false;
          }
  
          return ok;
      }
docs: <p>
  Opens the raster map and does some first checking
  </p>
  
  @return true if everything went alright