text: // Reducer definition.
  const tokenReducer = (state = null, action) => {
    switch (action.type) {
  
      // Stores JSON Web Token in state.
      case 'STORE_TOKEN':
        return action.payload;
  
      // Deletes JSON Web Token from state.
      case 'DELETE_TOKEN':
        return null;
  
      // Return empty state by default.
      default:
        return state;
    }
  };
  
  // Export reducer.
  export default tokenReducer;
  