code: def flush(self, epoch: int) -> None:
      if self._flush_function:
          self._flush_function(self, epoch)
      else:
          for reporter in self._reporters:
              reporter.flush(epoch)
  
file_path: ReAgent/reagent/reporting/compound_reporter.py
imports: from typing import Callable, List
  from reagent.core.result_registries import TrainingReport
  from .reporter_base import ReporterBase
label_desc: Use image node_id 4 for calling the CompoundReporter obj's underlying member method code with example usage: obj.flush(epoch) without return types