Old version of php on ucommxsrv1 doesnt like passing self::functionName as a parameter of usort()

src/UNL/Procurement/BuyerList.php

@@ -20,12 +20,13 @@ class UNL_Procurement_BuyerList extends ArrayIterator
             }
         }
         $mysqli->close();
-        usort($buyers,"self::uidSort");
-        return new self($buyers);
-    }
     
-    public static function uidSort($a,$b)
-    {
-        return strcmp(substr($a,1), substr($b,1));
+        function uidSort($a,$b)
+        {
+            return strcmp(substr($a,1), substr($b,1));
+        }
+        usort($buyers,"uidSort");
+
+        return new self($buyers);
     }
-}
\ No newline at end of file
+}