Issue in walker.php

[iswaq]

I have written walker.php which completely matchs to this WordPress101 Alecaddd repository's walker.php file. But i am facing the following issue. Please help

Strict Standards: Declaration of Walker_Nav_Primary::start_lvl() should be compatible with Walker_Nav_Menu::start_lvl(&$output, $depth = 0, $args = Array) in C:\xampp\htdocs\icatalog\wp-content\themes\sunsettheme\inc\walker.php on line 93

[VencaWoska]

fix: function start_lvl( &$output, $depth = 0, $args = array())