Can custom maps in Starcraft 2 automatically enable certain unit upgrades?

If I create a custom map with the Starcraft 2 map editor, how can I specify that some unit upgrades are already researched?

For example, if I want all the units to already have the weapons upgrade 1 at the beginning of the game, can I specify this in the editor?

I've looked through the menus but didn't find anything that looked like it would relate to unit upgrades.

To enable upgrades or set other special properties for a map you have to use a trigger that is executed at the start of the game.

In the map editor, Modules -> Triggers (F6) opens the trigger editor:

The only default trigger is "Melee Initialization", which is executed at the start of the game. New actions can be added to this trigger by choosing New -> New Action (Ctrl-R) in the right pane's context menu. Searching for "upgrade" brings up the correct action to add:

Double-clicking on Upgrade: (No Value) then shows a window that lets you choose which upgrade you want to enable for the player.

The action created this way will be executed at the start of the game and enable the selected upgrade.

There are two ways of doing this: editing the ability through the Unit (so you don't have to remember what it's called) and editing the ability directly. I'll go through unit because I think it's easier.

1. Push F7 (opens up Data Module)
2. "Units" tab is default. Type in the unit you're editing. I'm doing "Marine"
3. Once you start typing letters you'll notice the list get shorter. It's realtime search. Click on "Marine"
4. You'll notice the box UNDER the search results now looks like this:
   • Marine
     • Abilities
       • Attack
       • Marine-Stimpack
5. Right click on the ability you want, and select "View Linked Ability"

6. On the far right side of your screen you'll see a new list:

   • Ability: Commands +
   • Ability: Target Filters +
   • Ability A....."

   Double click on "Ability: Commands+"

7. Double click on "Ability: Execute+"
8. To the right of "Ability: Requirements" you'll see "Use Stimpack". Right click on "Use Stimpack" and click "Modify Value"
9. Now here's the easy, but easy to miss part. On the right side of this little window, about halfway down, just underneath the vertical scroll bar, is a tiny little red x. Can't find it? Put your finger in the middle of this window. Move it to the right until you.... ah ha! Find it. Click that. Click "OKAY". Your Marine now has stimpack.