React\Promise\FunctionReduceTest::shouldReduceValuesWithInitialPromise PHP Method

    public function shouldReduceValuesWithInitialPromise()
    {
        $mock = $this->createCallableMock();
        $mock->expects($this->once())->method('__invoke')->with($this->identicalTo(7));
        reduce([1, 2, 3], $this->plus(), resolve(1))->then($mock);
    }