This tests to make sure that after a deletion, merging can merge into an editable region that's embedded in non-editable content that is collapsed by the deletion.
| "\n"
| <table>
|   border="1"
|   contenteditable="false"
|   <tbody>
|     <tr>
|       <td>
|         <span>
|           contenteditable="true"
|           id="start"
|           "<#selection-caret>This sentence should be inside the editable cell."