# cat ./test.php
<?php


class Test1
{
  const PRIORITY = 100;

  public function getPriority()
  {
    return self::PRIORITY;
  }
}

class Test2 extends Test1
{
  const PRIORITY = 20;
}


$t1 = new Test1();
echo $t1->getPriority() . "\n";
$t2 = new Test2();
echo $t2->getPriority() . "\n";


# php ./test.php
100
100