First implementation of an atom feed

id.go

@@ -0,0 +1,16 @@
+package atomfeed
+
+import "errors"
+
+type ID struct {
+	*CommonAttributes
+	URI URI `xml:"uri"`
+}
+
+func (i *ID) Check() error {
+	if i.URI == "" {
+		return errors.New("uri element of id empty")
+	}
+
+	return nil
+}