code: private void printClassList(PrintStream out, Iterable<EntityIdValue> classes) {
  		out.print(",\"");
  		boolean first = true;
  		for (EntityIdValue superClass : classes) {
  			if (first) {
  				first = false;
  			} else {
  				out.print("@");
  			}
  			// makeshift escaping for Miga:
  			out.print(getClassLabel(superClass).replace("@", "＠"));
  		}
  		out.print("\"");
  	}
docs: Prints a list of classes to the given output. The list is encoded as a
  single CSV value, using "@" as a separator. Miga can decode this.
  Standard CSV processors do not support lists of entries as values,
  however.
  
  @param out
  the output to write to
  @param classes
  the list of class items