public function testApiReduce_ReducesPromisedInputValues_WithoutInitialValue()
{
$test = $this->getTest();
$mock = $test->createCallableMock();
$mock->expects($test->once())->method('__invoke')->with($test->identicalTo(6));
Promise::reduce([Promise::doResolve(1), Promise::doResolve(2), Promise::doResolve(3)], $this->plus())->then($mock);
}