XML : How to use ShouldSerialize on an array with multiple XmlElementAttribute

I'd like to use ShouldSerialize on the inp.bsn attribute as defined like this:

  [XmlElementAttribute("anp.identificatie", typeof(IdentificatieRPSBTLe), IsNullable=true)]  [XmlElementAttribute("authentiek", typeof(Authentiek), IsNullable=true)]  [XmlElementAttribute("inp.bsn", typeof(BSNe), IsNullable=true)]  public object[] Items {      get {          return this.itemsField;      }      set {          this.itemsField = value;      }  }    

How should I apply ShouldSerialize in cases like this?