/*
 * Get the RDF that was returned by the server of a MusicBrainz::Client object.
 *
 * Returns nil if a string could not be allocated or if there was an
 * error.
 * 
 * Aliases:
 *   MusicBrainz::Client#get_rdf
 *   MusicBrainz::Client#result_rdf
 *   MusicBrainz::Client#get_result_rdf
 *   
 * Example:
 *   rdf = mb.rdf
 *
 */
static VALUE mb_client_rdf(VALUE self) {