1 This test splits a text node by inserting a new paragraph and bolds the the first half.
2 If splitTextNode correctly reapplied the split, undo and redo should preserve the style. (See bug 42941).
6 | "<#selection-anchor>he<#selection-focus>"
11 | "he<#selection-caret>llo"
15 | "<#selection-anchor>he<#selection-focus>"