old_contents: import Component from '@ember/component';
  import { computed } from '@ember/object';
  
  import ol from 'openlayers';
  
  export default Component.extend({
    tagName: '',
  
    source: null,
    flight: null,
  
    feature: computed(function () {
      let flight = this.flight;
      return new ol.Feature({
        geometry: flight.get('geometry'),
        sfid: flight.get('id'),
        color: flight.get('color'),
        type: 'flight',
      });
    }),
  
    didInsertElement() {
      this._super(...arguments);
      this.source.addFeature(this.feature);
    },
  
    willDestroyElement() {
      this._super(...arguments);
      this.source.removeFeature(this.feature);
    },
  });
  
new_contents: import Component from '@glimmer/component';
  import ol from 'openlayers';
  
  export default class FlightPathLayerFeature extends Component {
    feature = new ol.Feature({
      geometry: this.args.flight.get('geometry'),
      sfid: this.args.flight.get('id'),
      color: this.args.flight.get('color'),
      type: 'flight',
    });
  
    constructor() {
      super(...arguments);
      this.args.source.addFeature(this.feature);
    }
  
    willDestroy() {
      super.willDestroy(...arguments);
      this.args.source.removeFeature(this.feature);
    }
  }
  
subject: Convert to Glimmer component