public void write(ProcessingInstruction processingInstruction) throws IOException {
        writeProcessingInstruction(processingInstruction);

        if ( autoFlush ) {
            flush();
        }
    }
Writes the given {@link ProcessingInstruction}.

@param processingInstruction <code>ProcessingInstruction</code> to output.
@throws IOException if the instruction could not be written
xmppserver/src/main/java/org/jivesoftware/util/XMLWriter.java