What is second part of GetUniquePlayerId().ToString() for in EOS?

[JediKnightChan]

Hi, I have the following code to get Epic Account ID

FString UECRGameInstance::GetUserAccountID()
{
	if (OnlineSubsystem)
	{
		if (const IOnlineIdentityPtr OnlineIdentityPtr = OnlineSubsystem->GetIdentityInterface())
		{
			const FUniqueNetIdPtr UniqueNetIdPtr = OnlineIdentityPtr->GetUniquePlayerId(0);
			return UECROnlineSubsystem::NetIdToString(UniqueNetIdPtr);
		}
	}
	return "";
}

However, it returns 2-part string, looking like “{epic_account_id}|{something_else_of_similar_length}”. What is the second part for?