SPCache using

I'm trying to use SPCache, I'm not getting the right example, 

I got only one example so far, http://msdn.microsoft.com/en-us/library/microsoft.office.server.objectcache.spcacheconfig.aspx

The example is incorrect, because put and get methods should have the first parameter as string, but here they are datatypes. I tried replacing datatypes with strings, but they failed. I tried with the DataType string "DataCache" and "String", both failed. Any idea how to use these get & put methods?