1--TEST-- 2Nullable return type inheritance rules (non-nullable and nullable) 3--FILE-- 4<?php 5class A { 6 function foo(): int {} 7} 8class B extends A { 9 function foo(): ?int {} 10} 11?> 12DONE 13--EXPECTF-- 14Fatal error: Declaration of B::foo(): ?int must be compatible with A::foo(): int in %s031.php on line 7 15