output: #fixed code
                                  public String getAppiumServerPath(String host) throws Exception {
         return appiumServerProp(host, "appiumServerPath");
      }
input: #vulnerable code 
                                  public String getAppiumServerPath(String host) throws Exception {
          JSONArray hostMachineObject = CapabilityManager.getInstance().getHostMachineObject();
          List<Object> objects = hostMachineObject.toList();
          Object o = objects.stream().filter(object -> ((HashMap) object).get("machineIP")
                  .toString().equalsIgnoreCase(host)
                  && ((HashMap) object).get("appiumServerPath") != null)
                  .findFirst().orElse(null);
          if (o != null) {
              return ((HashMap) o).get("appiumServerPath").toString();
          }
          return null;
      } 
                              #location 9 
                              #vulnerability type NULL_DEREFERENCE