Retrieves the #GObject instance used as the source of the binding.
A #GBinding can outlive the source #GObject as the binding does not hold a
strong reference to the source. If the source is destroyed before the
binding then this function will return null.
Retrieves the #GObject instance used as the source of the binding.
A #GBinding can outlive the source #GObject as the binding does not hold a strong reference to the source. If the source is destroyed before the binding then this function will return null.