text: export const UNDOABLE = 'RA/UNDOABLE';
  export const UNDO = 'RA/UNDO';
  export const COMPLETE = 'RA/COMPLETE';
  export const START_OPTIMISTIC_MODE = 'RA/START_OPTIMISTIC_MODE';
  export const STOP_OPTIMISTIC_MODE = 'RA/STOP_OPTIMISTIC_MODE';
  
  export const startUndoable = action => ({
      type: UNDOABLE,
      payload: { action },
  });
  
  export const undo = () => ({
      type: UNDO,
  });
  export const complete = () => ({
      type: COMPLETE,
  });
  
  export const startOptimisticMode = () => ({
      type: START_OPTIMISTIC_MODE,
  });
  
  export const stopOptimisticMode = () => ({
      type: STOP_OPTIMISTIC_MODE,
  });
  