async fetchResources() {
        const ops = [];
        debug('fetchResources');

        // NOTE: Iterate over all resource types (posts, users etc..) and call `_fetch`.
        _.each(this.resourcesConfig, (resourceConfig) => {
            this.data[resourceConfig.type] = [];

            // NOTE: We are querying knex directly, because the Bookshelf ORM overhead is too slow.
            ops.push(this._fetch(resourceConfig));
        });

        await Promise.all(ops);
    }
@description Helper function to initialize data fetching.