public boolean contains(String key){
  Assert.isTrue(allowedKeys.contains(key.toLowerCase()));
  return hashtable.containsKey(key.toLowerCase());
}

public boolean contains ( String key ) { Assert . isTrue ( allowedKeys . contains ( key . toLowerCase ( ) ) ) ; return hashtable . containsKey ( key . toLowerCase ( ) ) ; }
returns true if key is one of the parameters . case - insensitive .
