Paste selection from Office Word to web page, and JS ClipboardEvent will be triggered. If the selection contains "Heading" styles, like "Heading 1", "Heading 2", etc, ClipboardEvent rtf data will be empty.
Create Word document and type line1 and line2.
Apply line2 with 'Heading 1' style.
Copy all docuemnt content.
Paste to the demo page.
It print "Empty Content", but expect RTF text.
