private ByteBuffer verifyDataPassing(TCPChannel svrChan) throws Exception {
		ByteBuffer b = ByteBuffer.allocate(10);
		helper.putString(b, "de");
		helper.doneFillingBuffer(b);
		int expectedWrote = b.remaining();
		log.fine("***********************************************");
		int actualWrite = client1.oldWrite(b);
		assertEquals(expectedWrote, actualWrite);
		
		CalledMethod m = mockServer.expect(MockNIOServer.INCOMING_DATA);
		TCPChannel actualChannel = (TCPChannel)m.getAllParams()[0];
		Class c = Class.forName(getChannelImplName());
		assertEquals("should be correct type of channel", c, actualChannel.getClass());
		
		ByteBuffer actualBuf = (ByteBuffer)m.getAllParams()[1];
		String result = helper.readString(actualBuf, actualBuf.remaining());
		assertEquals("de", result);
		
		b.rewind();
		svrChan.oldWrite(b);
		
		m = mockHandler.expect(MockDataHandler.INCOMING_DATA);
		actualBuf = (ByteBuffer)m.getAllParams()[1];
		result = helper.readString(actualBuf, actualBuf.remaining());
		assertEquals("de", result);	
		return b;
	}