feat: implement platform handler creation

also refactor public and internal api to support transaction between
multiple methods

#2

pkg/collection.go

@@ -1,6 +1,25 @@
 package synchronizator
 
-import "fmt"
+import (
+	"fmt"
+	"strings"
+)
+
+type default_collection struct {
+	platform_name string
+}
+
+func (collection *default_collection) ToNode() (string, []byte, error) {
+	platform_name := strings.ToUpper(collection.platform_name)
+	return platform_name + "_DEFAULT", nil, nil
+}
+
+func (collection *default_collection) FromNode(_class string, name string, metadata []byte) error {
+	if _class != "DEFAULT" {
+		return fmt.Errorf("invalid class %s", _class)
+	}
+	return nil
+}
 
 // Utility struct to represent a collection of nodes, it's a [Node] itself so all
 // the node's functionality is available.
@@ -35,3 +54,16 @@ func (collection *Collection) AddChild(node *Node) error {
 
 	return nil
 }
+
+// Allows to retreive the saved information back into the user struct. This
+// method will call the [NodeClass.FromNode] of the provided struct.
+//
+// Example:
+//
+//	data := &Library{}
+//	if err := node.Unmarshall(data); err != nil {
+//		println(err)
+//	}
+func (collection *Collection) Unmarshall(dst StandardNode) error {
+	return dst.FromNode("COLLECTION", collection.name, collection.metadata)
+}