Sets the body message. As a side-effect the gio.types.DBusMessageHeaderField.Signature header field is set to the type string of body (or cleared if body is null).
If body is floating, message assumes ownership of body.
Either null or a #GVariant that is a tuple.
Sets the body message. As a side-effect the gio.types.DBusMessageHeaderField.Signature header field is set to the type string of body (or cleared if body is null).
If body is floating, message assumes ownership of body.