Holder.forceInvalidE
void forceInvalidE(glib.error.ErrorWrap error = null)Forces a holder to be invalid; to set it valid again, a new value must be assigned to it using gda.holder.Holder.setValue or gda.holder.Holder.takeValue.
holder's value is set to null.
Parameters
error | a #GError explaining why holder is declared invalid, or null |