Create NewPersion function

person.go

@@ -13,14 +13,20 @@ type Person struct {
 	Extensions []*ExtensionElement `xml:",any,omitempty"`
 }
 
+func NewPerson(name string) *Person {
+	return &Person{Name: name}
+}
+
 func (p *Person) Check() error {
 	if p.Name == "" {
 		return errors.New("name element of person element empty")
 	}
 
-	for i, e := range p.Extensions {
-		if err := e.Check(); err != nil {
-			return fmt.Errorf("extension element %v of person %v: %v", i, p.Name, err)
+	if p.Extensions != nil {
+		for i, e := range p.Extensions {
+			if err := e.Check(); err != nil {
+				return fmt.Errorf("extension element %v of person %v: %v", i, p.Name, err)
+			}
 		}
 	}