code: final WsResource getLTPAKeyFileResource(WsLocationAdmin locService, String ltpaKeyFile) {
          WsResource ltpaFile = locService.resolveResource(ltpaKeyFile);
          if (ltpaFile != null && ltpaFile.exists()) {
              return ltpaFile;
          } else {
              // The file does not exist so return null
              return null;
          }
      }
docs: Given the path to the LTPA key file return the WsResource for the file
  if the file exists.
  
  @param ltpaKeyFile
  
  @return WsResource if the file exist, null if it does not.