output: #fixed code
                                  public void debugHeader() {
          if (!traceDebugEnabled) {
              return;
          }
  
          System.out.println("---------------- Trace Information ---------------");
          String traceId = getTraceId();
          String spanId = getSpanId();
          System.out.println(DiscoveryConstant.TRACE_ID + "=" + (StringUtils.isNotEmpty(traceId) ? traceId : StringUtils.EMPTY));
          System.out.println(DiscoveryConstant.SPAN_ID + "=" + (StringUtils.isNotEmpty(spanId) ? spanId : StringUtils.EMPTY));
          System.out.println(DiscoveryConstant.N_D_SERVICE_GROUP + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_GROUP));
          System.out.println(DiscoveryConstant.N_D_SERVICE_TYPE + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_TYPE));
          System.out.println(DiscoveryConstant.N_D_SERVICE_ID + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_ID));
          System.out.println(DiscoveryConstant.N_D_SERVICE_ADDRESS + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_ADDRESS));
          System.out.println(DiscoveryConstant.N_D_SERVICE_VERSION + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_VERSION));
          System.out.println(DiscoveryConstant.N_D_SERVICE_REGION + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_REGION));
          System.out.println(DiscoveryConstant.N_D_SERVICE_ENVIRONMENT + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_ENVIRONMENT));
  
          String routeVersion = strategyContextHolder.getHeader(DiscoveryConstant.N_D_VERSION);
          if (StringUtils.isNotEmpty(routeVersion)) {
              System.out.println(DiscoveryConstant.N_D_VERSION + "=" + routeVersion);
          }
          String routeRegion = strategyContextHolder.getHeader(DiscoveryConstant.N_D_REGION);
          if (StringUtils.isNotEmpty(routeRegion)) {
              System.out.println(DiscoveryConstant.N_D_REGION + "=" + routeRegion);
          }
          String routeAddress = strategyContextHolder.getHeader(DiscoveryConstant.N_D_ADDRESS);
          if (StringUtils.isNotEmpty(routeAddress)) {
              System.out.println(DiscoveryConstant.N_D_ADDRESS + "=" + routeAddress);
          }
          String routeEnvironment = strategyContextHolder.getHeader(DiscoveryConstant.N_D_ENVIRONMENT);
          if (StringUtils.isNotEmpty(routeEnvironment)) {
              System.out.println(DiscoveryConstant.N_D_ENVIRONMENT + "=" + routeEnvironment);
          }
          String routeVersionWeight = strategyContextHolder.getHeader(DiscoveryConstant.N_D_VERSION_WEIGHT);
          if (StringUtils.isNotEmpty(routeVersionWeight)) {
              System.out.println(DiscoveryConstant.N_D_VERSION_WEIGHT + "=" + routeVersionWeight);
          }
          String routeRegionWeight = strategyContextHolder.getHeader(DiscoveryConstant.N_D_REGION_WEIGHT);
          if (StringUtils.isNotEmpty(routeRegionWeight)) {
              System.out.println(DiscoveryConstant.N_D_REGION_WEIGHT + "=" + routeRegionWeight);
          }
  
          Map<String, String> customizationMap = getCustomizationMap();
          if (MapUtils.isNotEmpty(customizationMap)) {
              for (Map.Entry<String, String> entry : customizationMap.entrySet()) {
                  System.out.println(entry.getKey() + "=" + entry.getValue());
              }
          }
          System.out.println("--------------------------------------------------");
      }
input: #vulnerable code 
                                  public void debugHeader() {
          if (!traceDebugEnabled) {
              return;
          }
  
          System.out.println("---------------- Trace Information ---------------");
          String traceId = getTraceId();
          String spanId = getSpanId();
          System.out.println(DiscoveryConstant.TRACE_ID + "=" + (StringUtils.isNotEmpty(traceId) ? traceId : StringUtils.EMPTY));
          System.out.println(DiscoveryConstant.SPAN_ID + "=" + (StringUtils.isNotEmpty(spanId) ? spanId : StringUtils.EMPTY));
          System.out.println(DiscoveryConstant.N_D_SERVICE_GROUP + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_GROUP));
          System.out.println(DiscoveryConstant.N_D_SERVICE_TYPE + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_TYPE));
          System.out.println(DiscoveryConstant.N_D_SERVICE_ID + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_ID));
          System.out.println(DiscoveryConstant.N_D_SERVICE_ADDRESS + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_ADDRESS));
          System.out.println(DiscoveryConstant.N_D_SERVICE_VERSION + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_VERSION));
          System.out.println(DiscoveryConstant.N_D_SERVICE_REGION + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_REGION));
          System.out.println(DiscoveryConstant.N_D_SERVICE_ENVIRONMENT + "=" + strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_ENVIRONMENT));
  
          String routeVersion = strategyContextHolder.getHeader(DiscoveryConstant.N_D_VERSION);
          if (StringUtils.isNotEmpty(routeVersion)) {
              System.out.println(DiscoveryConstant.N_D_VERSION + "=" + routeVersion);
          }
          String routeRegion = strategyContextHolder.getHeader(DiscoveryConstant.N_D_REGION);
          if (StringUtils.isNotEmpty(routeRegion)) {
              System.out.println(DiscoveryConstant.N_D_REGION + "=" + routeRegion);
          }
          String routeAddress = strategyContextHolder.getHeader(DiscoveryConstant.N_D_ADDRESS);
          if (StringUtils.isNotEmpty(routeAddress)) {
              System.out.println(DiscoveryConstant.N_D_ADDRESS + "=" + routeAddress);
          }
          String routeVersionWeight = strategyContextHolder.getHeader(DiscoveryConstant.N_D_VERSION_WEIGHT);
          if (StringUtils.isNotEmpty(routeVersionWeight)) {
              System.out.println(DiscoveryConstant.N_D_VERSION_WEIGHT + "=" + routeVersionWeight);
          }
          String routeRegionWeight = strategyContextHolder.getHeader(DiscoveryConstant.N_D_REGION_WEIGHT);
          if (StringUtils.isNotEmpty(routeRegionWeight)) {
              System.out.println(DiscoveryConstant.N_D_REGION_WEIGHT + "=" + routeRegionWeight);
          }
  
          Map<String, String> customizationMap = getCustomizationMap();
          if (MapUtils.isNotEmpty(customizationMap)) {
              for (Map.Entry<String, String> entry : customizationMap.entrySet()) {
                  System.out.println(entry.getKey() + "=" + entry.getValue());
              }
          }
          System.out.println("--------------------------------------------------");
      } 
                              #location 42 
                              #vulnerability type NULL_DEREFERENCE