A DESCRIPTION OF THE PROBLEM :
The sentence "The Enumerations returned by Hashtable's keys and values methods are not fail-fast." seems to be invalid. The method values does not return an Enumeration as mentioned in the sentence instead it returns a Collection.

It seems that the sentence should of used "elements" instead of "values" since the method element returns an Enumeration.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
"The Enumerations returned by Hashtable's keys and elements methods are not fail-fast."
ACTUAL -
"The Enumerations returned by Hashtable's keys and values methods are not fail-fast."

URL OF FAULTY DOCUMENTATION :
http://java.sun.com/j2se/1.5.0/docs/api/java/util/Hashtable.html