text: import { c3_chart_fn } from './core';
  
  c3_chart_fn.show = function (targetIds, options) {
      var $$ = this.internal, targets;
  
      targetIds = $$.mapToTargetIds(targetIds);
      options = options || {};
  
      $$.removeHiddenTargetIds(targetIds);
      targets = $$.svg.selectAll($$.selectorTargets(targetIds));
  
      targets.transition()
          .style('display', 'initial', 'important')
          .style('opacity', 1, 'important')
          .call($$.endall, function () {
              targets.style('opacity', null).style('opacity', 1);
          });
  
      if (options.withLegend) {
          $$.showLegend(targetIds);
      }
  
      $$.redraw({withUpdateOrgXDomain: true, withUpdateXDomain: true, withLegend: true});
  };
  
  c3_chart_fn.hide = function (targetIds, options) {
      var $$ = this.internal, targets;
  
      targetIds = $$.mapToTargetIds(targetIds);
      options = options || {};
  
      $$.addHiddenTargetIds(targetIds);
      targets = $$.svg.selectAll($$.selectorTargets(targetIds));
  
      targets.transition()
          .style('opacity', 0, 'important')
          .call($$.endall, function () {
              targets.style('opacity', null).style('opacity', 0);
              targets.style('display', 'none');
          });
  
      if (options.withLegend) {
          $$.hideLegend(targetIds);
      }
  
      $$.redraw({withUpdateOrgXDomain: true, withUpdateXDomain: true, withLegend: true});
  };
  
  c3_chart_fn.toggle = function (targetIds, options) {
      var that = this, $$ = this.internal;
      $$.mapToTargetIds(targetIds).forEach(function (targetId) {
          $$.isTargetToShow(targetId) ? that.hide(targetId, options) : that.show(targetId, options);
      });
  };
  