code: @SuppressWarnings("resource")
      private InputStream loadFile(String trustStorePath) throws FileNotFoundException {
          InputStream input;
          try {
              input = new FileInputStream(trustStorePath);
          } catch (FileNotFoundException e) {
              LOGGER.warn("File {} not found. Fallback to classpath.", trustStorePath);
              input = Thread.currentThread().getContextClassLoader().getResourceAsStream(trustStorePath);
          }
          if (input == null) {
              throw new FileNotFoundException("File " + trustStorePath + " does not exist");
          }
          return input;
      }
docs: This method is used to find file from disk or classpath.
  
  @param trustStorePath
  file to load
  @return instance of {@link InputStream} containing content of the file
  @throws FileNotFoundException
  if file does not exist