GVariant * g_variant_ref (GVariant *value);
GVariant * g_variant_ref_sink (GVariant *value);
gboolean g_variant_is_floating (GVariant *value);
+GVariant * g_variant_take_ref (GVariant *value);
const GVariantType * g_variant_get_type (GVariant *value);
const gchar * g_variant_get_type_string (GVariant *value);