code: @Test public void testBasicWrite() throws Exception {
    SessionOutputBufferMock transmitter=new SessionOutputBufferMock();
    IdentityOutputStream outstream=new IdentityOutputStream(transmitter);
    outstream.write(new byte[]{'a','b'},0,2);
    outstream.write('c');
    outstream.flush();
    byte[] input=transmitter.getData();
    Assert.assertNotNull(input);
    byte[] expected=new byte[]{'a','b','c'};
    Assert.assertEquals(expected.length,input.length);
    for (int i=0; i < expected.length; i++) {
      Assert.assertEquals(expected[i],input[i]);
    }
  }
  