diff --git a/repository/Grafoscopio-Utils/GrafoscopioUtils.class.st b/repository/Grafoscopio-Utils/GrafoscopioUtils.class.st
index 95ca750..a700e79 100644
--- a/repository/Grafoscopio-Utils/GrafoscopioUtils.class.st
+++ b/repository/Grafoscopio-Utils/GrafoscopioUtils.class.st
@@ -8,7 +8,7 @@ Class {
 	#category : #'Grafoscopio-Utils'
 }
 
-{ #category : #'as yet unclassified' }
+{ #category : #utilities }
 GrafoscopioUtils class >> checksumFor: aFileReference [
 	^ (SHA1 new hashMessage: aFileReference binaryReadStream contents) hex.
 ]
@@ -51,6 +51,17 @@ GrafoscopioUtils class >> getContentsFrom: url withMessage: aString [
 	^ client contents.
 ]
 
+{ #category : #utilities }
+GrafoscopioUtils class >> perform: aString on: anObject [
+
+	| msg |
+	msg := self selectorAndArgumentsFrom: aString.
+	msg 
+		at: 'args'
+		ifPresent: [ ^ anObject perform: (msg at: 'selector') withArguments: (msg at: 'args') ]
+		ifAbsent: [ ^ anObject perform: (msg at: 'selector') ]
+]
+
 { #category : #private }
 GrafoscopioUtils class >> sanitize: url [
 	"I remove white spaces in url's and prepend 'http://' to urls when it is ommited, so
@@ -65,6 +76,25 @@ GrafoscopioUtils class >> sanitize: url [
 	^ sanitized
 ]
 
+{ #category : #utilities }
+GrafoscopioUtils class >> selectorAndArgumentsFrom: aString [
+	"I return from aString a symbol that contains a message and an array of arguments used in it"
+	| msgArray answer |
+	answer := OrderedDictionary new.
+	msgArray := aString splitOn: ':'.
+	msgArray size = 1 
+		ifTrue: [ 
+			^ answer
+				at: 'selector' put: (msgArray at: 1) asSymbol;
+				yourself ].
+	msgArray size = 2
+		ifTrue: [ 
+			^ answer
+				at: 'selector' put: ((msgArray at: 1),':') asSymbol;
+				at: 'args' put: (Array with: (msgArray at: 2)); 
+				yourself ].
+]
+
 { #category : #updating }
 GrafoscopioUtils class >> update [
 	"Updates GrafoscopioUtils with new versions of itself take from the source code repository."