'Args:
key (str or iterable): The Nick key or keys to check for.
category (str): Limit the check to Nicks with this
category (note, that `None` is the default category).
Returns:
has_nick (bool or list): If the Nick exists on this object
or not. If `key` was given as an iterable then the return
is a list of booleans.'

def has(self, key, category='inputline'):

    return super(NickHandler, self).has(key, category=category)
