Sets the body @message. As a side-effect the %G_DBUS_MESSAGE_HEADER_FIELD_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.
2.26
See Implementation
Sets the body @message. As a side-effect the %G_DBUS_MESSAGE_HEADER_FIELD_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.