node /org/freedesktop/timesync1 {
  interface org.freedesktop.timesync1.Manager {
    methods:
      SetRuntimeNTPServers(in  as runtime_servers);
    properties:
      readonly as LinkNTPServers = ['...', ...];
      readonly as SystemNTPServers = ['...', ...];
      readonly as RuntimeNTPServers = ['...', ...];
      readonly as FallbackNTPServers = ['...', ...];
      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
      readonly s ServerName = '...';
      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
      readonly (iay) ServerAddress = ...;
      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")
      readonly t RootDistanceMaxUSec = ...;
      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")
      readonly t PollIntervalMinUSec = ...;
      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")
      readonly t PollIntervalMaxUSec = ...;
      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
      readonly t PollIntervalUSec = ...;
      readonly (uuuuittayttttbtt) NTPMessage = ...;
      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
      readonly x Frequency = ...;
  };
  interface org.freedesktop.DBus.Peer { ... };
  interface org.freedesktop.DBus.Introspectable { ... };
  interface org.freedesktop.DBus.Properties { ... };
};

$ gdbus introspect --system \
  --dest org.freedesktop.timesync1 \
  --object-path /org/freedesktop/timesync1