output: #fixed code
                                  public void sendMessage(CommandIssuer issuer, MessageType type, MessageKeyProvider key, String... replacements) {
          String message = formatMessage(issuer, type, key, replacements);
  
          for (String msg : ACFPatterns.NEWLINE.split(message)) {
              issuer.sendMessageInternal(ACFUtil.rtrim(msg));
          }
      }
input: #vulnerable code 
                                  public void sendMessage(CommandIssuer issuer, MessageType type, MessageKeyProvider key, String... replacements) {
          String message = getLocales().getMessage(issuer, key.getMessageKey());
          if (replacements.length > 0) {
              message = ACFUtil.replaceStrings(message, replacements);
          }
  
          message = getCommandReplacements().replace(message);
  
          MessageFormatter formatter = formatters.getOrDefault(type, defaultFormatter);
          if (formatter != null) {
              message = formatter.format(message);
          }
  
          for (String msg : ACFPatterns.NEWLINE.split(message)) {
              issuer.sendMessageInternal(msg);
          }
      } 
                              #location 11 
                              #vulnerability type NULL_DEREFERENCE