'L{SingleRangeStaticProducer.start} writes at most
C{abstract.FileDescriptor.bufferSize} bytes of content from the
resource to the request at once.'

def test_resumeProducingBuffersOutput(self):

    request = DummyRequest([])
    bufferSize = abstract.FileDescriptor.bufferSize
    content = ('abc' * bufferSize)
    producer = static.SingleRangeStaticProducer(request, StringIO(content), 1, (bufferSize + 10))
    producer.start()
    expected = [content[1:(bufferSize + 1)], content[(bufferSize + 1):(bufferSize + 11)]]
    self.assertEqual(expected, request.written)
