code: public Extensions getOrCreate() {
  
  		// Create the attributes table
  		if (!geoPackage.isTable(TABLE_NAME)) {
  
  			AttributesColumn propertyColumn = AttributesColumn.createColumn(1,
  					COLUMN_PROPERTY, GeoPackageDataType.TEXT, true, null);
  			AttributesColumn valueColumn = AttributesColumn.createColumn(2,
  					COLUMN_VALUE, GeoPackageDataType.TEXT, false, null);
  
  			List<AttributesColumn> additionalColumns = new ArrayList<>();
  			additionalColumns.add(propertyColumn);
  			additionalColumns.add(valueColumn);
  
  			List<UserUniqueConstraint<AttributesColumn>> uniqueConstraints = new ArrayList<>();
  			uniqueConstraints.add(new UserUniqueConstraint<AttributesColumn>(
  					propertyColumn, valueColumn));
  
  			geoPackage.createAttributesTableWithId(TABLE_NAME,
  					additionalColumns, uniqueConstraints);
  		}
  
  		Extensions extension = getOrCreate(EXTENSION_NAME, TABLE_NAME, null,
  				EXTENSION_DEFINITION, ExtensionScopeType.READ_WRITE);
  
  		return extension;
  	}
docs: Get or create the extension
  
  @return extension