code: def restore_used_registers(self):
          
          used = self.used_registers_stack.pop()
          self.used_registers = used[:]
          used.sort(reverse = True)
          for reg in used:
              self.newline_text("POP \t%s" % SharedData.REGISTERS[reg], True)
              self.free_registers.remove(reg)
docs: Pops all used working registers after function call