human
Solve the following python programming problem given the following code:
def milestone_stats_data(env, req, stat, name, grouped_by = 'component', group = None) : 
    from trac.ticket.query import QueryModule 
    has_query = (env [QueryModule] is not None) 
    def query_href(extra_args) : 
        if (not has_query) : 
            return None 
args = { 
            'milestone' : name, 
            grouped_by : group, 
            'group' : 'status', 
} 
        args.update (extra_args) 
        return req.href.query (args) 
return { 
        'stats' : stat, 
        'stats_href' : query_href (stat.qry_args), 
        'interval_hrefs' : [query_href (query_href ['qry_args']) for interval in stat.intervals], 
} 

    
    

    Fix the buggy line: 'interval_hrefs' : [query_href (query_href ['qry_args']) for interval in stat.intervals] ,
assistant
#Here is Python program to fix the buggy line: 'interval_hrefs' : [query_href (query_href ['qry_args']) for interval in stat.

'interval_hrefs' : [query_href (interval ['qry_args']) for interval in stat.intervals] ,