This tests to see if position:sticky and position:fixed don't get converted to position:static and position:absolute upon copy/paste when there is only a partial selection (not the entire body is selected)

Before:
| "\nabc"
| <div>
|   style="position: fixed; left: 0px; top: 0px;"
|   "def"
| "ghi\n"

After:
| "abc"
| <div>
|   style="position: fixed; left: 0px; top: 0px;"
|   "def"
| "ghi<#selection-caret>"