Left Over Roll

Why cant asian places give you a bamboo mat, sushi rice, and seaweed/nori at the end of your meal so you can make left over rolls???

For example, I get peking duck and i cant finish it. Out comes the nori, some rice and a bamboo mat and if necessary some instructions and you can make you peking duck roll. Think of the possabilities...you own shrimp tempura roll, or katsu don rolls. You could even take the american general tso's chicken to make rolls. Lets say you get fish in a black bean sauce, you can chop up the fish sauce it upa little and roll into a great late night snack.

Some areas of concern might be noodle dishes, but i think this idea is genius.