Holder.setDefaultValue
void setDefaultValue(gobject.value.Value value)Sets the default value within the holder. If value is null then holder won't have a default value anymore. To set a default value to null, then pass a #GValue created using [gda.global.valueNewNull].
NOTE: the default value does not need to be of the same type as the one required by holder.
Parameters
value | a value to set the holder's default value, or null |