DateRange
class DateRange
An EXT-X-DATERANGE tag of an HLS media playlist (RFC 8216, section 4.3.2.7), such as the SCTE-35 ad marker a live encoder writes at a cue point.
Dates are epoch milliseconds. Durations are milliseconds, or -1 when the tag does not carry the attribute. All attributes of the tag, including those this class does not interpret, are available through attributes with the quotes of quoted-string values removed.