public function get_speakers( $attr, $speaker_ids ) {
		// Fetch all specified speakers.
		$speaker_args = [
			'post_type'      => Plugin::SPEAKER_POSTTYPE,
			'posts_per_page' => (int) $attr['posts_per_page'],
			'orderby'        => $attr['orderby'],
			'order'          => $attr['order'],
		];

		if ( ! empty( $attr['track'] ) ) {
			$speaker_args['post__in'] = empty( $speaker_ids ) ? [ 0 ] : $speaker_ids;
		}

		// phpcs:disable WordPress.DB.SlowDBQuery.slow_db_query_tax_query
		if ( ! empty( $attr['groups'] ) ) {
			$speaker_args['tax_query'] = [
				[
					'taxonomy' => Plugin::GROUP_TAXONOMY,
					'field'    => 'slug',
					'terms'    => $attr['groups'],
				],
			];
		}
		// phpcs:enable WordPress.DB.SlowDBQuery.slow_db_query_tax_query

		return new WP_Query( $speaker_args );
	}