code: public static boolean hasGeoPackageExtension(File file) {
  		String extension = GeoPackageIOUtils.getFileExtension(file);
  		boolean isGeoPackage = extension != null
  				&& (extension
  						.equalsIgnoreCase(GeoPackageConstants.GEOPACKAGE_EXTENSION) || extension
  						.equalsIgnoreCase(GeoPackageConstants.GEOPACKAGE_EXTENDED_EXTENSION));
  		return isGeoPackage;
  	}
docs: Check the file extension to see if it is a GeoPackage
  
  @param file
  GeoPackage file
  @return true if GeoPackage extension