404         result += key_value_build("v=", Some(&self.version.to_string())).as_str();  in marshal()
405         result += key_value_build("o=", Some(&self.origin.to_string())).as_str();  in marshal()
406         result += key_value_build("s=", Some(&self.session_name)).as_str();  in marshal()
408         result += key_value_build("i=", self.session_information.as_ref()).as_str();  in marshal()
411             result += key_value_build("u=", Some(&format!("{uri}"))).as_str();  in marshal()
413         result += key_value_build("e=", self.email_address.as_ref()).as_str();  in marshal()
414         result += key_value_build("p=", self.phone_number.as_ref()).as_str();  in marshal()
416             result += key_value_build("c=", Some(&connection_information.to_string())).as_str();  in marshal()
420             result += key_value_build("b=", Some(&bandwidth.to_string())).as_str();  in marshal()
423             result += key_value_build("t=", Some(&time_description.timing.to_string())).as_str();  in marshal()
425                 result += key_value_build("r=", Some(&repeat_time.to_string())).as_str();  in marshal()
433             result += key_value_build("z=", Some(&time_zones.join(" "))).as_str();  in marshal()
435         result += key_value_build("k=", self.encryption_key.as_ref()).as_str();  in marshal()
437             result += key_value_build("a=", Some(&attribute.to_string())).as_str();  in marshal()
442                 key_value_build("m=", Some(&media_description.media_name.to_string())).as_str();  in marshal()
443             result += key_value_build("i=", media_description.media_title.as_ref()).as_str();  in marshal()
445                 result += key_value_build("c=", Some(&connection_information.to_string())).as_str();  in marshal()
448                 result += key_value_build("b=", Some(&bandwidth.to_string())).as_str();  in marshal()
450             result += key_value_build("k=", media_description.encryption_key.as_ref()).as_str();  in marshal()
452                 result += key_value_build("a=", Some(&attribute.to_string())).as_str();  in marshal()