code: def _rollback(self):
          
          last_pc, last_gas, last_instruction, last_arguments, fee, allocated = self._checkpoint_data
          self._push_arguments(last_arguments)
          self._gas = last_gas
          self._pc = last_pc
          self._allocated = allocated
          self._checkpoint_data = None
docs: Revert the stack, gas, pc and memory allocation so it looks like before executing the instruction