chromium/third_party/blink/web_tests/external/wpt/webvtt/rendering/cues-with-video/processing-model/support/bold_with_2_timestamps.vtt

WEBVTT

00:00:00.000 --> 00:00:10.000
<00:00.000><b>This is a </b><00:05.000><b>test subtitle</b>