=== Good ===

TC_001_WEBVTTNoBOM- Webvtt file without optional BOM

TC_002_WEBVTTWithBom - Webvtt file with optional BOM

TC_003_WEBVTTHead - Webvtt file starts with peoper WEBVTT header

TC_004_WEBVTTSpace - Webvtt file can have a space after proper WEBVTT header

TC_005_WEBVTTTab - Webvtt file can have a tab after proper WEBVTT header

TC_007_WEBVTTSpaceText - Webvtt header may be followed by a space and text

TC_008_WEBVTTTabText - Webvtt header may be followed by a tab and text

=== Bad ===