Program crash when nocache=False

[chjuncn]

In paper-demo.py,

when I use nocache=False in

    records, execution_stats = Execute(
        plan,
        policy,
        **nocache=False,**
        optimization_strategy=OptimizationStrategy.PARETO,
        execution_engine=execution_engine,
        verbose=verbose,
    )

I got error:

  File "/Users/chjun/Documents/GitHub/palimpzest/src/palimpzest/query/execution/nosentinel_execution.py", line 67, in execute
    records, plan_stats = self.execute_strategy(dataset, policy, optimizer)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/chjun/Documents/GitHub/palimpzest/src/palimpzest/query/execution/execution_engine.py", line 200, in execute_strategy
    records, plan_stats = self.execute_plan(
                          ^^^^^^^^^^^^^^^^^^
  File "/Users/chjun/Documents/GitHub/palimpzest/src/palimpzest/query/execution/plan_executors/parallel_plan_execution.py", line 139, in execute_plan
    self.datadir.append_cache(operator.target_cache_id, record)
  File "/Users/chjun/Documents/GitHub/palimpzest/src/palimpzest/datamanager/datamanager.py", line 234, in append_cache
    self._tempCache[cache_id].append(data)
    ~~~~~~~~~~~~~~~^^^^^^^^^^
KeyError: None