diff --git a/src/MiniDocs/GrafoscopioNode.class.st b/src/MiniDocs/GrafoscopioNode.class.st
index 9202e6b..280d2f4 100644
--- a/src/MiniDocs/GrafoscopioNode.class.st
+++ b/src/MiniDocs/GrafoscopioNode.class.st
@@ -12,11 +12,20 @@ Class {
 		'created',
 		'nodesInPreorder',
 		'selected',
-		'edited'
+		'edited',
+		'headers',
+		'key',
+		'output'
 	],
 	#category : #MiniDocs
 }
 
+{ #category : #accessing }
+GrafoscopioNode class >> fromFile: aFileReference [
+
+	^ (STON fromString: aFileReference contents) first parent
+]
+
 { #category : #accessing }
 GrafoscopioNode >> ancestors [
 	"I return a collection of all the nodes wich are ancestors of the receiver node"
@@ -104,7 +113,9 @@ GrafoscopioNode >> created: anObject [
 GrafoscopioNode >> earliestCreationDate [
 	| earliest |
 	
-	earliest := self nodesWithCreationDates first created.
+	self nodesWithCreationDates ifNotEmpty: [
+	earliest := self nodesWithCreationDates first created]
+	ifEmpty: [ earliest := self ].
 	self nodesWithCreationDates do: [:node |
 		node created <= earliest ifTrue: [ earliest := node created ] ].
 	^ earliest