/*
* Set the length of an audio stream (in seconds).
*
* Note: This method is optional, but if it is called, it must be called
* after MusicBrainz::TRM#pcm_data and before any calls to
* MusicBrainz::TRM#generate_signature.
*
* Aliases:
* MusicBrainz::TRM#set_length
* MusicBrainz::TRM#song_length=
* MusicBrainz::TRM#set_song_length
*
* Examples:
* trm.length = 4000
*/
static VALUE mb_trm_set_length(VALUE self, VALUE len) {