A ver:
1)
Código PHP:
class Bar{
}
class Foo extends Bar{
}
2)
Código PHP:
class Bar{
public static function getInstance(){
return new self();
}
}
class Foo extends Bar{
function __construct(){
parent::getInstance();
}
}
3)
Código PHP:
class Bar{
}
class Foo extends Bar{
function __construct(){
return new Bar;
}
}