--TEST-- Exceptions on improper usage of $this --FILE-- --EXPECTF-- Error: Cannot call abstract method C::foo() in %s:%d Stack trace: #0 {main} TypeError: Argument 1 passed to foo() must be callable, string given, called in %s on line %d and defined in %s:%d Stack trace: #0 %s(%d): foo('C::foo') #1 {main} Fatal error: Uncaught Error: Cannot call abstract method C::foo() in %s:%d Stack trace: #0 {main} thrown in %s on line %d