Create needed functions for common attributes and their extensions

commonAttributes.go

@@ -8,6 +8,22 @@ type CommonAttributes struct {
 	UndefinedAttributes []*ExtensionAttribute `xml:",any"`
 }
 
+// NewCommonAttributes creates a new set of CommonAttributes. It returns a
+// *CommonAttributes.
+func NewCommonAttributes() *CommonAttributes {
+	return new(CommonAttributes)
+}
+
+// AddExtensionAttribute adds the ExtensionAttribute to the CommonAttributes.
+func (c *CommonAttributes) AddExtensionAttribute(e *ExtensionAttribute) {
+	if c.UndefinedAttributes == nil {
+		c.UndefinedAttributes = make([]*ExtensionAttribute, 1)
+		c.UndefinedAttributes[0] = e
+	} else {
+		c.UndefinedAttributes = append(c.UndefinedAttributes, e)
+	}
+}
+
 // Check checks the CommonAttributes for incompatibilities with RFC4287. It
 // returns an error.
 func (c *CommonAttributes) Check() error {