Sorry if I'm asking what might seem a very basic question, but I need some help

I want to process 4-hour tradebars (NOT 4 one-hour bars!), how do I specify that to LEAN? I tried this in the compiler, and it accepts it, but Im not at all sure Im do this the right way

AddSecurity(SecurityType.Forex, symArr[i], (Resolution)Period.FourHours);