Program: 35538
Project: 35538
Buggy source:
public void registerExtenderCallbacks(final IBurpExtenderCallbacks callbacks){
  this.callbacks=callbacks;
  helpers=callbacks.getHelpers();
  callbacks.setExtensionName("String_Node_Str");
  callbacks.registerContextMenuFactory(this);
  callbacks.registerExtensionStateListener(this);
  callbacks.registerHttpListener(this);
  stdout=new PrintWriter(callbacks.getStdout(),true);
  stderr=new PrintWriter(callbacks.getStderr(),true);
  stdout.println("String_Node_Str");
  stdout.println("String_Node_Str");
  stdout.println("String_Node_Str");
  stdout.println("String_Node_Str");
  stdout.println("String_Node_Str");
  initializeCurrentCollaboratorVariables();
  if (!(currentCollaboratorType.equals("String_Node_Str"))) {
    collaboratorContext=callbacks.createBurpCollaboratorClientContext();
  }
 else {
    collaboratorContext=null;
  }
  processedRequestResponse=new HashMap<String,IHttpRequestResponsePersisted>();
  interactionServer=new InteractionServer(callbacks,processedRequestResponse,collaboratorContext);
  interactionServer.start();
  if (collaboratorContext == null) {
    interactionServer.pause();
    interactionServerNeverStarted=true;
  }
 else {
    interactionServerNeverStarted=false;
  }
  SwingUtilities.invokeLater(new Runnable(){
    @Override public void run(){
      mainPanel=new JPanel();
      mainPanel.setLayout(new BoxLayout(mainPanel,BoxLayout.Y_AXIS));
      JPanel innerPanel=new JPanel();
      innerPanel.setLayout(new BoxLayout(innerPanel,BoxLayout.Y_AXIS));
      innerPanel.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
      JLabel pollingTitleLabel=new JLabel("String_Node_Str");
      pollingTitleLabel.setForeground(new Color(249,130,11));
      pollingTitleLabel.setFont(new Font("String_Node_Str",Font.BOLD,16));
      pollingTitleLabel.setAlignmentX(Component.LEFT_ALIGNMENT);
      JLabel enablePollingLabel=new JLabel();
      String enablePollingLabelContent="String_Node_Str" + "String_Node_Str" + "String_Node_Str"+ "String_Node_Str"+ "String_Node_Str"+ "String_Node_Str";
      enablePollingLabel.setText("String_Node_Str" + enablePollingLabelContent + "String_Node_Str");
      enablePollingLabel.setBorder(BorderFactory.createEmptyBorder(10,0,0,0));
      enablePolling=new JCheckBox("String_Node_Str");
      enablePolling.setSelected(true);
      enablePolling.setActionCommand("String_Node_Str");
      enablePolling.addActionListener(BurpExtender.this);
      enablePolling.setBorder(BorderFactory.createEmptyBorder(10,0,0,0));
      innerPanel.add(pollingTitleLabel);
      innerPanel.add(enablePollingLabel);
      innerPanel.add(enablePolling);
      mainPanel.add(innerPanel);
      callbacks.customizeUiComponent(mainPanel);
      callbacks.addSuiteTab(BurpExtender.this);
    }
  }
);
}

Fixed version (ground truth):
public void registerExtenderCallbacks(final IBurpExtenderCallbacks callbacks){
  this.callbacks=callbacks;
  helpers=callbacks.getHelpers();
  callbacks.setExtensionName("String_Node_Str");
  callbacks.registerContextMenuFactory(this);
  callbacks.registerExtensionStateListener(this);
  callbacks.registerHttpListener(this);
  stdout=new PrintWriter(callbacks.getStdout(),true);
  stderr=new PrintWriter(callbacks.getStderr(),true);
  stdout.println("String_Node_Str");
  stdout.println("String_Node_Str");
  stdout.println("String_Node_Str");
  stdout.println("String_Node_Str");
  stdout.println("String_Node_Str");
  initializeCurrentCollaboratorVariables();
  if (!(currentCollaboratorType.equals("String_Node_Str"))) {
    collaboratorContext=callbacks.createBurpCollaboratorClientContext();
  }
 else {
    collaboratorContext=null;
  }
  processedRequestResponse=new HashMap<String,IHttpRequestResponsePersisted>();
  interactionServer=new InteractionServer(callbacks,processedRequestResponse,collaboratorContext);
  interactionServer.start();
  SwingUtilities.invokeLater(new Runnable(){
    @Override public void run(){
      mainPanel=new JPanel();
      mainPanel.setLayout(new BoxLayout(mainPanel,BoxLayout.Y_AXIS));
      JPanel innerPanel=new JPanel();
      innerPanel.setLayout(new BoxLayout(innerPanel,BoxLayout.Y_AXIS));
      innerPanel.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
      JLabel pollingTitleLabel=new JLabel("String_Node_Str");
      pollingTitleLabel.setForeground(new Color(249,130,11));
      pollingTitleLabel.setFont(new Font("String_Node_Str",Font.BOLD,16));
      pollingTitleLabel.setAlignmentX(Component.LEFT_ALIGNMENT);
      JLabel enablePollingLabel=new JLabel();
      String enablePollingLabelContent="String_Node_Str" + "String_Node_Str" + "String_Node_Str"+ "String_Node_Str"+ "String_Node_Str"+ "String_Node_Str";
      enablePollingLabel.setText("String_Node_Str" + enablePollingLabelContent + "String_Node_Str");
      enablePollingLabel.setBorder(BorderFactory.createEmptyBorder(10,0,0,0));
      enablePolling=new JCheckBox("String_Node_Str");
      enablePolling.setSelected(true);
      enablePolling.setActionCommand("String_Node_Str");
      enablePolling.addActionListener(BurpExtender.this);
      enablePolling.setBorder(BorderFactory.createEmptyBorder(10,0,0,0));
      innerPanel.add(pollingTitleLabel);
      innerPanel.add(enablePollingLabel);
      innerPanel.add(enablePolling);
      mainPanel.add(innerPanel);
      callbacks.customizeUiComponent(mainPanel);
      callbacks.addSuiteTab(BurpExtender.this);
    }
  }
);
}