Stateful service for generating OME-XML or OME-TIFF from data stored
 in OMERO. Intended usage:
 
 
 ExporterPrx e = sf.createExporter();
 // Exporter is currently in the <i>configuration</i> state
 // Objects can be added by id which should be present
 // in the output.
 e.addImage(1);
 // As soon as a generate method is called, the objects
 // added to the Exporter are converted to the specified
 // format. The length of the file produced is returned.
 // No more objects can be added to the Exporter, nor can
 // another generate method be called.
 long length = e.generateTiff();
 // As soon as the server-side file is generated, read()
 // can be called to get file segments. To create another
 // file, create a second Exporter. Be sure to close all
 // Exporter instances.
 long read = 0
 byte\[] buf;
 while (true) {
 buf = e.read(read, 1000000);
 // Store to file locally here
 if (buf.length < 1000000) {
 break;
 }
 read += buf.length;
 }
 e.close();