text: /**
   * Returns true if the query string change was performed by a history navigation.
   *
   * @param {object} state - Current state.
   * @param {object} action - Dispatched action.
   * @returns {object} Updated state.
   */
  export function isHistoryNavigation( state = false, action ) {
  	switch ( action.type ) {
  		case 'INITIALIZE_QUERY_VALUES':
  			// Triggered by SearchApp.handleHistoryNavigation.
  			return action.isHistoryNavigation;
  		case 'SET_SEARCH_QUERY':
  		case 'SET_SORT':
  		case 'CLEAR_FILTERS':
  		case 'SET_FILTER':
  			// A query string update is invoked to the window, creating a history state.
  			// In other words, the query string change was performed by UI interaction.
  			// It was *not* performed by a history navigation.
  			return action.propagateToWindow ? false : state;
  	}
  
  	return state;
  }
  