Recursive calls to a method which creates a graph instance

I’m a VB.Net guy, so this is probably more of a C# question.

On my processing page, I am calling a static void method.  In that method a graph instance is created.  This method might be called 100 times.

public static void DoIt(List<ICSCustomers> custList, RecordsToProcessFilter currentFilter) 
{ 
    var graph = PXGraph.CreateInstance<CustomersProcess>();

    //CODE 
}

After the DoIt method is completed, does the graph instance get destroyed, or does it stay in memory?  I am concerned that if I have 100 instances of that graph in memory it will cause problems.

If it does stay in memory, is there a way to destroy it at the end of the method?  I see I can “clear” it, but that isn’t the same as destroying it.

Thanks!

Joe