get availablePreviewTypes() {
        const previewTypes = [{
            name: 'homepage',
            label: 'Homepage'
        }];

        // in case we haven't loaded any posts so far
        if (!this.latestPublishedPost) {
            this.loadLastPostTask.perform();
        }

        if (this.latestPublishedPost) {
            previewTypes.push({
                name: 'post',
                label: 'Post'
            });
        }

        return previewTypes;
    }
Contains the active theme object (includes warnings and errors)