text: import { handleActions } from 'redux-actions';
  import { INCREMENT_COUNTER, DECREMENT_COUNTER } from '../constants';
  import { fromJS } from 'immutable';
  
  const counterReducer = handleActions({
    [INCREMENT_COUNTER]: (state) =>
      state.update('count', (value) =>
        value + 1),
    [DECREMENT_COUNTER]: (state) =>
      state.update('count', (value) =>
        value - 1),
  }, fromJS({
    count: 0,
  }));
  
  export default counterReducer;
  