code: public void removeExtension(String geoPackage) {
  		PropertiesCoreExtension<T, ?, ?, ?> properties = propertiesMap
  				.get(geoPackage);
  		if (properties != null) {
  			properties.removeExtension();
  		}
  	}
docs: Remove the extension from a specified GeoPackage
  
  @param geoPackage
  GeoPackage name