Get the contents of a G_TYPE_BOXED derived GValue. Upon getting,
the boxed value is duplicated and needs to be later freed with
g_boxed_free(), e.g. like: g_boxed_free (G_VALUE_TYPE (value), return_value);
This method is not directly available to language bindings.
Return value
Type:gpointer
Boxed contents of value.
The caller of the method takes ownership of the data, and is responsible for freeing it.