[libgee] Fix first() and last() signatures in AbstractList

[Didier 'Ptitjes' Villevalois <dvillevalois src gnome org>]

commit 93122ef684cc81555d1978348405e1d057745610
Author: Didier 'Ptitjes <ptitjes free fr>
Date:   Sat Sep 19 17:18:22 2009 +0200

    Fix first() and last() signatures in AbstractList

 gee/abstractlist.vala |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gee/abstractlist.vala b/gee/abstractlist.vala
index 23d491e..fcc02d6 100644
--- a/gee/abstractlist.vala
+++ b/gee/abstractlist.vala
@@ -69,14 +69,14 @@ public abstract class Gee.AbstractList<G> : Gee.AbstractCollection<G>, List<G> {
 	/**
 	 * @inheritDoc
 	 */
-	public virtual G? first () {
+	public virtual G first () {
 		return get (0);
 	}
 
 	/**
 	 * @inheritDoc
 	 */
-	public virtual G? last () {
+	public virtual G last () {
 		return get (size - 1);
 	}