Removed "DoubleCheckedLocking", because it is not valid anymore.
diff --git a/conf/checkstyle/sun_checks.xml b/conf/checkstyle/sun_checks.xml
index 79bef41..51a7f8c 100644
--- a/conf/checkstyle/sun_checks.xml
+++ b/conf/checkstyle/sun_checks.xml
@@ -145,7 +145,6 @@
         <!-- Checks for common coding problems               -->

         <!-- See http://checkstyle.sf.net/config_coding.html -->

         <module name="AvoidInlineConditionals"/>

-        <module name="DoubleCheckedLocking"/>    <!-- MY FAVOURITE -->

         <module name="EmptyStatement"/>

         <module name="EqualsHashCode"/>

         <module name="HiddenField"/>