Source

File: wp-admin/includes/class-wp-posts-list-table.php

private function _display_rows( $posts, $level = 0 ) {
		$post_type = $this->screen->post_type;

		// Create array of post IDs.
		$post_ids = array();

		foreach ( $posts as $a_post ) {
			$post_ids[] = $a_post->ID;
		}

		if ( post_type_supports( $post_type, 'comments' ) ) {
			$this->comment_pending_count = get_pending_comments_num( $post_ids );
		}

		foreach ( $posts as $post ) {
			$this->single_row( $post, $level );
		}
	}