nl_tokens: This may be called by a parent generator to trigger / propagate cancellation cancel all pending tasks ( including the main task ) then end the current task .
pl_tokens: function cancel ( ) { /**
        We need to check both Running and Cancelled status
        Tasks can be Cancelled but still Running
      **/ if ( iterator . _isRunning && ! iterator . _isCancelled ) { iterator . _isCancelled = true taskQueue . cancelAll ( ) /**
          Ending with a Never result will propagate the Cancellation to all joiners
        **/ <mask> ( TASK_CANCEL ) } }