Revert "Go directly through #empty? instead of #readable?."
Revert "Go directly through #empty? instead of #readable?."

This reverts commit 7c9ed85163354244805498de77a8375e4dc292fd.
ichannel has removed the #empty? method because #readable? is suffice
and is a more accurate description of what the method is asking.

havenwood/xpool