Fatal error themes hueman functions widgets alx-tabs.php

I Re-install the theme still the error is there how can i solve that problem

Fatal error: Cannot declare class AlxTabs, because the name is already in use in /home/basas/public_html/wp-content/themes/hueman/functions/widgets/alx-tabs.php on line 420

and i updated my wordpress i am using version 5.0.3 last version please help me for that error

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