Add specific jquery.ui dependency to theme

I’m trying to add a toggle() with a slide function in my Drupal 8.5 theme and it’s not working very well. I go to the browser console and see thousands of errors like this:

TypeError: r.easing[this.easing] is not a function.

Searching I find that it’s likely because the easing plugin is not loaded. Looking at my page source I see many files being pulled in from /core/assets/vendor/jquery.ui/ui/* but nothing from /effects/ let alone /effects/slider

I’ve followed the pointer found here… but find no matter what syntax I use and cache rebuilding all each time it does not seem to load it.

In my theme.libraries.yml

  Version: 1.x
      css/global.css: {}
      css/media.css: {}
    js/jquery.smartmenus.min.js: {}
    js/custom.js: {}
    - core/jquery
    - core/drupal.ajax
    - core/drupal
    - core/drupalSettings
    - core/jquery.once
    - core/modernizr
    - core/jquery.ui.slide

And the global-components is loaded in my as I’ve only added one dependency to the working existing. What am I doing wrong? sam

Drupal version: