I need a mu-plugin to hide a menu item

Hey guys,

I need a small code snippet to hide 'Domain Mapping' menu item under 'Tools' parent menu. You can see it in here, http://bit.ly/2hVJJwb Just create a test site and visit Tools menu.

Here's a screen cap of domain mapping page I want to hide from all network sites: http://prnt.sc/drrkaw

Wish you all a happy new year!