nltk "OMW" wordnet with Arabic language

I'm working on python/nltk with (OMW) wordnet specifically for The Arabic language. All the functions work fine with the English language yet I can't seem to be able to perform any of them when I use the 'arb' tag. The only thing that works great is extracting the lemma_names from a given Arabic synset.

The code below works fine with u'arb': The output is a list of Arabic lemmas.

for synset in wn.synsets(u'عام',lang=('arb')):
    for lemma in synset.lemma_names(u'arb'):
        print lemma

When I try to perform the same logic as the code above with synset, definitions, example, hypernyms, I get an error which says:

TypeError: hyponyms() takes exactly 1 argument (2 given)

(if I supply the 'arb' flag) or

KeyError: u'arb'

This is one of the codes that will not work if I write synset.hyponyms(u'arb'):

for synset in wn.synsets(u'عام',lang=('arb')):
    for hypo in synset.hyponyms(): #print the hyponyms in English not Arabic
        print hypo

Does this mean that I can't get to use wn.all_synsets and other built-in functions to extract all the Arabic synsets, hypernyms, etc?