This test setting a suggested value on an input element.
The dump below should have the "suggested value" instead of "initial value".
| <input>
|   id="test"
|   type="text"
|   value="initial value"
|   this.value="initial value"
|   <shadow:root>
|     <div>
|       "suggested value"
| "input.value: initial value"
| "internals.suggestedValue(input): suggested value"
| "input.selectionStart: 0"
| "input.selectionEnd: 0"