How to use the tokenizers.camel.__call__ function in tokenizers

def rec_length(key, value):
        if key not in lengths:
            lengths[key] = []
        if value is None:
            length = 0
        else:
            length = len(camel.__call__(value))
        lengths[key].append((crash['database_id'], length))
        if value is not None:
            #print(key + " " + value + " " + str(length), file=sys.stderr)
            if key not in ulengths:
                ulengths[key] = dict()
            ulengths[key][value] = length