diff --git a/object/object.go b/object/object.go
index 640c9a9..42ffe28 100644
--- a/object/object.go
+++ b/object/object.go
@@ -86,3 +86,13 @@ func DefinitionFromSpec(specification Specification) *Definition {
 type DefinitionHolder interface {
 	Definition() *Definition
 }
+
+type Definitions []DefinitionHolder
+
+func (c Definitions) Len() int      { return len(c) }
+func (c Definitions) Swap(i, j int) { c[i], c[j] = c[j], c[i] }
+func (c Definitions) Less(i, j int) bool {
+	return c[i].Definition().Selector.Priority > c[j].Definition().Selector.Priority ||
+		(c[i].Definition().Selector.Priority == c[j].Definition().Selector.Priority &&
+			c[i].Definition().MetaData.Name > c[j].Definition().MetaData.Name)
+}