Chart component yielding selection is not handled by child chart component correctly

[ming-codes]

{{#data-visual as |stage width height|}}
  {{#parent-chart select=stage.svg.select.chart as |selection|}}
    {{child-chart-component select=selection}}
  {{/parent-chart}}
{{/data-visual}}

// parent-chart.js
Ember.Component.extend({
  call(selection) {
    this.set('yieldDown', selection.append('g'));
  }
})

// parent-chart.hbs
{{yield yieldDown}}

This is expected to work, but it doesn't. Because select= is expecting a selection proxy.

Do this instead.

// parent-chart.js
Ember.Component.extend({
  call(selection) {
    selection.append('g').classed('cls');

    this.set('yieldDown', this.get('select.cls'));
  }
})

This will make the select proxy correctly wrap the element to yield down.