classes.php

<?php

function sc_configure($instance) {
  $instance
    ->configure();
}
class BarClass {
  protected $baz;
  public function setBaz(BazClass $baz) {
    $this->baz = $baz;
  }
  public function getBaz() {
    return $this->baz;
  }

}
class BazClass {
  protected $foo;
  public function setFoo(Foo $foo) {
    $this->foo = $foo;
  }
  public function configure($instance) {
    $instance
      ->configure();
  }
  public static function getInstance() {
    return new self();
  }
  public static function configureStatic($instance) {
    $instance
      ->configure();
  }
  public static function configureStatic1() {
  }

}
class BarUserClass {
  public $bar;
  public function __construct(BarClass $bar) {
    $this->bar = $bar;
  }

}