eKey());
    utils.normalizeStyleAttributeValues();
    assert_in_array(
      editingHost.innerHTML,
      t.expectedHTML(`style="${rightWhiteSpace}"`),
      "white-space should be preserved by <span> elements"
    );
  }, `${commandName} at ${t.initialHTML.replace(/\n/g, "\\n")}`);

  if (rightWhiteSpaceClass !== null) {
    // Replace style attribute with class attribute.
    const initialHTMLWithClass =
      t.initialHTML.replace(
        rightStyleAttr,
        `class="${rightWhiteSpaceClass}"`
     