A DESCRIPTION OF THE PROBLEM :
Replace "javax.xml.stream.Attribute" (which does not exist) by "javax.xml.stream.events.Attribute" (which exists and is actually what is returned)
You could also link to that interface.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
javax.xml.stream.events.Attribute
ACTUAL -
javax.xml.stream.Attribute

URL OF FAULTY DOCUMENTATION :
https://docs.oracle.com/javase/8/docs/api/javax/xml/stream/events/StartElement.html#getAttributes--