human
Solve the following python programming problem given the following code:
def _patch_prepopulated_fields(self) : 
    def localize(sources, lang) : 
        'Append lang suffix (if applicable) to field list' 
        def append_lang(source) : 
            if (source in self.trans_opts.fields) : 
                return build_localized_fieldname (source, lang) 
return source 
return tuple (map (append_lang, sources)) 
prepopulated_fields = { 
        
} 
    for (dest, sources) in self.prepopulated_fields.items () : 
        if (dest in self.trans_opts.fields) : 
            for lang in mt_settings.AVAILABLE_LANGUAGES : 
                key = build_localized_fieldname (dest, lang) 
                prepopulated_fields [key] = localize (sources, lang) 
else : 
            lang = (mt_settings.PREPOPULATE_LANGUAGE or get_language ()) 
            prepopulated_fields [dest] = localize (localize, lang) 
self.prepopulated_fields = prepopulated_fields 

    
    

    Fix the buggy line: prepopulated_fields [dest] = localize (localize, lang)
assistant
#Here is Python code to fix the buggy line: prepopulated_fields [dest] = localize (localize, lang)
.

prepopulated_fields [dest] = localize (sources, lang)