src/vs/workbench/contrib/customEditor/browser/customEditors.ts/CustomEditorService/getUserConfiguredCustomEditors
class CustomEditorService:	public getUserConfiguredCustomEditors(resource: URI): CustomEditorInfoCollection {
		const resourceAssocations = this.extensionContributedEditorService.getAssociationsForResource(resource);
		return new CustomEditorInfoCollection(
			coalesce(resourceAssocations
				.map(association => this._contributedEditors.get(association.viewType))));
	}