code: public User initialize(String authCode, String redirectUri) throws WorkspaceApiException {
          return initialize(authCode, redirectUri, null, null);
      }
docs: Initialize the API using the provided authorization code and redirect URI. The authorization code comes from using the
  Authorization Code Grant flow to authenticate with the Authentication API.
  @param authCode The authorization code you received during authentication.
  @param redirectUri The redirect URI you used during authentication. Since this is not sent by the UI, it needs to match the redirectUri that you sent when using the Authentication API to get the authCode.
  @return CompletableFuture<User>