xwiki/xwiki-rendering — comment on commit 13e9d53fdfa599d05dfcd42298501212baeb6f98
File: xwiki-rendering-transformations/xwiki-rendering-transformation-linkchecker/src/main/java/org/xwiki/rendering/internal/transformation/linkchecker/DefaultHTTPChecker.java line 58
By sdumitriu:

This means that you must make sure that the client is thread-safe. Right now it isn't, see http://hc.apache.org/httpclient-3.x/threading.html