#vulnerable code 
                                public void setupSensibleDefaultPty() {
        try {
            String os = System.getProperty("os.name").toLowerCase();
            if (os.indexOf("windows") < 0) {
                ptyModes = SttySupport.getUnixPtyModes();
                ptyColumns = SttySupport.getTerminalWidth();
                ptyLines = SttySupport.getTerminalHeight();
            } else {
                ptyType = "windows";
            }
        } catch (Throwable t) {
            // Ignore exceptions
        }
    } 
                            #location 3 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public void setupSensibleDefaultPty() {
        try {
            if (OsUtils.isUNIX()) {
                ptyModes = SttySupport.getUnixPtyModes();
                ptyColumns = SttySupport.getTerminalWidth();
                ptyLines = SttySupport.getTerminalHeight();
            } else {
                ptyType = "windows";
            }
        } catch (Throwable t) {
            // Ignore exceptions
        }
    }