data.value = handler;
textHolder.value = "Hi";
headerHolder.value = "Header";
port.echoDataWithHeader(textHolder, data, headerHolder);
InputStream bis = null;
bis = data.value.getDataSource().getInputStream();
byte b[] = new byte[10];
bis.read(b, 0, 10);
String string = IOUtils.newStringFromBytes(b);