Just installed — said fatal error on line 44

I just installed the plugin and it said it could not activate due to a fatal error on line 44.

Parse error: syntax error, unexpected T_STATIC, expecting ')' in /homepages/5/d501990179/htdocs/fergusoncomputers/wp-content/plugins/testimonials-widget/lib/aihrus/class-aihrus-common.php on line 44

My host provider is 1&1 and in the global PHP version settings it says 5.4, so I don’t think it’s an issue w/ php 5.2.

Any recommendations as to what else I should troubleshoot?

https://www.ads-software.com/plugins/testimonials-widget/