code: @Test public void testChunkNoExceed() throws Exception {
    ByteArrayOutputStream baos=new ByteArrayOutputStream();
    WritableByteChannel channel=newChannel(baos);
    HttpParams params=new BasicHttpParams();
    SessionOutputBuffer outbuf=new SessionOutputBufferImpl(1024,16,params);
    HttpTransportMetricsImpl metrics=new HttpTransportMetricsImpl();
    ChunkEncoder encoder=new ChunkEncoder(channel,outbuf,metrics);
    encoder.write(wrap("1234"));
    encoder.complete();
    outbuf.flush(channel);
    String s=baos.toString("US-ASCII");
    Assert.assertTrue(encoder.isCompleted());
    Assert.assertEquals("4\r\n1234\r\n0\r\n\r\n",s);
  }
  