code: private boolean checkAppPathsForVia(Set<String> keySet, List<String> errors) {
          for (String key : keySet) {
              if (!key.equals("defaultKey")) {
                  File file = new File(key);
                  if (!file.exists()) {
                      errors.add("Effective Usage Analysis will not run if the -appPath parameter references an invalid file path. Check that the -appPath parameter specifies a valid path");
                      return false;
                  } else if (!file.isFile()) {
                      errors.add("Effective Usage Analysis will not run if the -appPath parameter references an invalid file path. Check that the -appPath parameter specifies a valid path");
                      return false;
                  } else {
                      return true;
                  }
              }
          }
          return false;
      }
docs: check validation for appPath property, first check if the path is exist and then if this path is not a directory