code: @Override
      public OAuthToken get(String envKey) {
          try
          {
             FileInputStream fileIn = new FileInputStream(getFilePath(envKey));
             ObjectInputStream in = new ObjectInputStream(fileIn);
             OAuthToken token = (OAuthToken) in.readObject();
             in.close();
             fileIn.close();
             return token;
          } catch (Exception ex)
          {
              return null; // it's not an error: e.g. file not found cause not stored yet
          }
      }
docs: Gets the currently stored token.
  @param envKey Environment key for token.
  @return Currently stored token instance or null.