### Question:
RackResponsePropagator { private void propagateBody(RackResponse rackResponse, HttpServletResponse response) { ServletOutputStream outputStream = null; try { outputStream = response.getOutputStream(); } catch (IOException e) { Throwables.propagate(e); } Iterator<byte[]> body = rackResponse.getBody(); while (body.hasNext()) { try { outputStream.write(body.next()); } catch (IOException e) { Throwables.propagate(e); } } try { outputStream.flush(); } catch (IOException e) { Throwables.propagate(e); } }  void propagate(RackResponse rackResponse, HttpServletResponse response);  }### Answer:
@Test public void propagateBody() throws IOException { rackResponse.body("Here ".getBytes(), "are ".getBytes(), "the ".getBytes(), "parts.".getBytes()); subject.propagate(rackResponse.build(), response); InOrder inOrder = inOrder(outputStream); inOrder.verify(outputStream).write("Here ".getBytes()); inOrder.verify(outputStream).write("are ".getBytes()); inOrder.verify(outputStream).write("the ".getBytes()); inOrder.verify(outputStream).write("parts.".getBytes()); inOrder.verify(outputStream).flush(); }