fixed static call

git-svn-id: https://plugins.svn.wordpress.org/documentation/trunk@973252 b8457f37-d9ea-0310-8a92-e5e31aec5664
tagged 1.3.1

git-svn-id: https://plugins.svn.wordpress.org/documentation/trunk@973253 b8457f37-d9ea-0310-8a92-e5e31aec5664