public function testReturnsZeroWhenDecisionMakerReturnsTrueButNoFurtherStrategiesAreInTheChain() { $a = new CallbackBackoffStrategy(function () { return null; }, true); $b = new CallbackBackoffStrategy(function () { return true; }, true); $a->setNext($b); $this->assertSame(0, $a->getBackoffPeriod(2, new Request('GET', 'http://www.foo.com'))); }