This tests inserting elements with font-weight set to lighter and bolder values
Content to insert:
| <span>
| style="font-weight: lighter;"
| "hello"
| <span>
| style="font-weight: bolder;"
| "world"
After insertion:
| <span>
| style="font-weight: lighter;"
| "hello"
| <span>
| style="font-weight: bolder;"
| "world<#selection-caret>"