to accommodate a modular heater embodiment such as those shown in FIGS. 1,4,5, and 6; FIG. 14A is a plan view of a container portion in a form of a can end having a pocket formed therein having protrusions to facilitate retention of a modular heater therein; FIG. 14B is is a cross-sectional assembly view of the container portion of FIG. 14A and a modular heater; FIG. 15 is a perspective assembly