comment-in-cue-text
<link rel="help" href="https://www.w3.org/TR/webvtt1/#introduction-comments">

assert_equals(cues.length, 2);

assert_equals(cues[0].text, 'NOTE text');
assert_equals(cues[0].startTime, 0);
assert_equals(cues[0].endTime, 1);

assert_equals(cues[1].text, 'NOTE text\nNOTE text2');
assert_equals(cues[1].startTime, 1);
assert_equals(cues[1].endTime, 2);

===
WEBVTT

NOTE this is real comment that should be ignored

00:00:00.000 --> 00:00:01.000
NOTE text

NOTE
this is also a real comment that should be ignored
this is also a real comment that should be ignored

00:00:01.000 --> 00:00:02.000
NOTE text
NOTE text2