Provides a struct to hold virtual memory data.
## Examples
iex> sm = %ExFacts.System.Mem.SwapMemStat{total: 320000, used: 6000, free: 26000} ...> sm.free 26000
t() :: %ExFacts.System.Mem.SwapMemStat{free: integer, sin: integer, sout: integer, total: integer, used: integer, used_percent: float}