text: /**
   * A custom router reducer to support an Immutable store.
   */
  import { fromJS } from 'immutable';
  import { LOCATION_CHANGE } from 'react-router-redux';
  
  const initialState = fromJS({
      locationBeforeTransitions: null
  });
  
  export default (state = initialState, action) => {
      if (action.type === LOCATION_CHANGE) {
          return state.merge({
              locationBeforeTransitions: action.payload
          });
      }
  
      return state;
  };
  