Add "after" to filter.

@@ -10,6 +10,8 @@ import java.util.List;
 public final class Filter {
 // ------------------------------ FIELDS ------------------------------
 
+    private long after;
+
     private List<Condition> conditions = new ArrayList<Condition>();
 
     private long maxResults;
@@ -116,11 +118,20 @@ public final class Filter {
         if (maxResults > 0) {
             builder.append("&max=").append(maxResults);
         }
+        if (after > 0) {
+            builder.append("&after=").append(after);
+        }
         return builder.length() > space.length() ? builder.substring(space.length()) : builder.toString();
     }
 
 // -------------------------- OTHER METHODS --------------------------
 
+    public Filter after(long after)
+    {
+        this.after = after;
+        return this;
+    }
+
     public Filter created(DateValues date)
     {
         return created(date.getFilterValue());