Pops from the stack and returns the popped thing. The length will be the architecture word size.

def stack_pop(self):
        """
        Pops from the stack and returns the popped thing. The length will be the architecture word size.
        """
        sp = self.regs.sp
        self.regs.sp = sp - self.arch.stack_change
        return self.memory.load(sp, self.arch.bytes, endness=self.arch.memory_endness)