+ In case of a setup packet, it contains a Setup Tag. If scripts read a number
+ in this field, they proceed to read Data Length. Otherwise, they read
+ the setup packet before reading the Data Length.
+- Setup packet, if present, consists of 5 words: one of each for bmRequestType,
+ bRequest, wValue, wIndex, wLength, as specified by the USB Specification 2.0.
+ These words are safe to decode if Setup Tag was 's'. Otherwise, the setup
+ packet was present, but not captured, and the fields contain filler.