<summary>
Set underline.
</summary>
<param name="hasUnderline">The Boolean flag indicates whether underline takes place</param>
<param name="textRange">Text range to which this change applies.</param>
<returns>
Standard HRESULT error code.
</returns>
<summary> Set underline. </summary> <param name="hasUnderline">The Boolean flag indicates whether underline takes place</param> <param name="textRange">Text range to which this change applies.</param> <returns> Standard HRESULT error code. </returns>