class Example { public static $prop = "Hello, world!"; public static function getProp() { return self::$prop; } } // Call the static property: echo Example::$prop; // Outputs "Hello, world!" // Call the static method: echo Example::getProp(); // Outputs "Hello, world!"This example uses the static keyword to define the property and method as belonging to the class itself, rather than to a particular instance of the class. The self keyword is used to reference the static property within the static method. The package library for this example is likely to be the core PHP language, as the static keyword is a fundamental feature of the language.