code: public synchronized void saveHostFile() throws IOException {
  		if (!hostFileWriteable) {
  			throw new IOException("Host file is not writeable.");
  		}
  
  		try {
  			File f = new File(knownhosts);
  
  			FileOutputStream out = new FileOutputStream(f);
  
  			out.write(toString().getBytes());
  
  			out.close();
  		} catch (IOException e) {
  			throw new IOException("Could not write to " + knownhosts);
  		}
  	}
docs: <p>
  Save's the host key file to be saved.
  </p>
  
  @throws InvalidHostFileException
  if the host file is invalid
  
  @since 0.2.0