Port everything over to AsXml

parsers/src/ping.rs

@@ -5,14 +5,14 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-use xso::{FromXml, IntoXml};
+use xso::{AsXml, FromXml};
 
 use crate::iq::IqGetPayload;
 use crate::ns;
 
 /// Represents a ping to the recipient, which must be answered with an
 /// empty `<iq/>` or with an error.
-#[derive(FromXml, IntoXml, PartialEq, Debug, Clone)]
+#[derive(FromXml, AsXml, PartialEq, Debug, Clone)]
 #[xml(namespace = ns::PING, name = "ping")]
 pub struct Ping;