So every time I try to run xl-net using the run_generation.py script, I get the warning : FutureWarning: This config doesn't use attention memories, a core feature of XLNet. Consider setting mem_len to a non-zero value, for example xlnet = XLNetLMHeadModel.from_pretrained('xlnet-base-cased'', mem_len=1024), for accurate training performance as well as an order of magnitude faster inference.

The issue is that I am using mem_len, I'm setting it to 384 (have tried other values as well) but I still get this warning.