Alternative to unifiedFile in EPIServer 10

Is there anyone expert in EPIServer.

I need help to migrate code from Version 6 to 10.

I have this code in my file and it gives error after i migrated to Version 10.

public void Initialize(InitializationEngine context)
    {
        UnifiedFile.UnifiedFileCheckedIn += UnifiedFile_UnifiedFileCheckedIn;
    }

It gives error on UnifiedFile.The name unifiedfile does not exist in current context. 

Like this many errors related to it. 

What is alternative for this?