code: @Deprecated
      public static BoxDeveloperEditionAPIConnection getAppUserConnection(String userId, String clientId,
          String clientSecret, JWTEncryptionPreferences encryptionPref) {
  
          BoxDeveloperEditionAPIConnection connection = new BoxDeveloperEditionAPIConnection(userId,
              DeveloperEditionEntityType.USER, clientId, clientSecret, encryptionPref);
  
          connection.authenticate();
  
          return connection;
      }
docs: Creates a new Box Developer Edition connection with App User token.
  @param userId                the user ID to use for an App User.
  @param clientId              the client ID to use when exchanging the JWT assertion for an access token.
  @param clientSecret          the client secret to use when exchanging the JWT assertion for an access token.
  @param encryptionPref        the encryption preferences for signing the JWT.
  @return a new instance of BoxAPIConnection.
  
  @deprecated Use the version of this method that accepts an IAccessTokenCache to prevent unneeded
  requests to Box for access tokens.