Problem: it was hard to debug new_zpl
Problem: it was hard to debug new_zpl

Solution: add an assert to check if it returned an instance

zeromq/zproto,sappo/zproto,vyskocilm/zproto,zeromq/zproto,sappo/zproto,jdiez17/zproto,jdiez17/zproto,somdoron/zproto,bkmit/zproto,zeromq/zproto,somdoron/zproto,vyskocilm/zproto,sappo/zproto,bkmit/zproto,bkmit/zproto,bkmit/zproto,vyskocilm/zproto,zeromq/zproto,sappo/zproto,jdiez17/zproto,jdiez17/zproto,sappo/zproto,jdiez17/zproto,sappo/zproto,vyskocilm/zproto,somdoron/zproto,vyskocilm/zproto,bkmit/zproto,jdiez17/zproto,zeromq/zproto,zeromq/zproto,bkmit/zproto,zeromq/zproto,somdoron/zproto,sappo/zproto,vyskocilm/zproto,somdoron/zproto,bkmit/zproto,vyskocilm/zproto,somdoron/zproto,jdiez17/zproto,somdoron/zproto