This doesn\'t work:
interface TestInterface { public function testMethod(); } interface TestInterface2 { public function testMethod(); } class Test
It appears that current PHP versions actually can do this. I've tracked the change in behavior down to this commit:
https://github.com/php/php-src/commit/31ef559712dae57046b6377f07634ad57f9d88cf#Zend/zend_compile.c
So as of php-5.3.9 the documented behavior appears to have changed.