code: func (v *Container) ChildGetProperty(child IWidget, name string, valueType glib.Type) (interface{}, error) {
  	gv, e := glib.ValueInit(valueType)
  	if e != nil {
  		return nil, e
  	}
  	cstr := C.CString(name)
  	defer C.free(unsafe.Pointer(cstr))
  
  	C.gtk_container_child_get_property(v.native(), child.toWidget(), (*C.gchar)(cstr), (*C.GValue)(unsafe.Pointer(gv.Native())))
  	return gv.GoValue()
  }
docs: // ChildGetProperty is a wrapper around gtk_container_child_get_property().