A DESCRIPTION OF THE PROBLEM :
Documentation related to this method
public static Pattern compile(String regex,int flags)
is not correct.

You can see this description:
Throws:
    IllegalArgumentException - If bit values other than those corresponding to the defined match flags are set in flags

while java.util.regex.Pattern never raises this excception.



URL OF FAULTY DOCUMENTATION :
http://download.oracle.com/javase/6/docs/api/java/util/regex/Pattern.html