code: def _runDeferredFunctions(deferredFunctions):
          
          failures = []
          for deferredFunction in deferredFunctions:
              try:
                  deferredFunction.invoke()
              except:
                  failures.append(deferredFunction.name)
                  logger.exception('%s failed.', deferredFunction)
          return failures
docs: Invoke the specified deferred functions and return a list of names of functions that
          raised an exception while being invoked.
  
          :param list[DeferredFunction] deferredFunctions: the DeferredFunctions to run
          :rtype: list[str]