Prooph\EventStore\Adapter\InMemoryAdapter::appendTo PHP Method

    public function appendTo(StreamName $streamName, Iterator $domainEvents)
    {
        if (!isset($this->streams[$streamName->toString()])) {
            throw new StreamNotFoundException(sprintf('Stream with name %s cannot be found', $streamName->toString()));
        }
        $appendIterator = new AppendIterator();
        $appendIterator->append($this->streams[$streamName->toString()]);
        $appendIterator->append($domainEvents);
        $this->streams[$streamName->toString()] = $appendIterator;
    }

 /**
  * @test
  * @expectedException Prooph\EventStore\Exception\StreamNotFoundException
  */
 public function it_throws_exception_when_trying_to_append_on_non_existing_stream()
 {
     $streamName = $this->prophesize(StreamName::class);
     $streamName->toString()->willReturn('test');
     $this->adapter->appendTo($streamName->reveal(), []);
 }