code: private InputStream openFile() throws IOException {
      Path file = Paths.get(filePath);
      if (Files.exists(file)) {
        return Files.newInputStream(file);
      }
      InputStream input = getClass().getResourceAsStream(filePath);
      checkArgument(input != null, "Could not find file: " + filePath);
      return input;
    }
docs: Returns the input stream for the raw file.