final List<String> sides = split(line, "=>");
                if (sides.size() > 1) { // explicit mapping
                    if (sides.size() != 2) {
                        throw new DictionaryException("more than one explicit mapping specified on the same line");
                    }
                    final List<String> inputStrings = split(sides.get(0), ",");
                    inputs = new String[inputStrings.size()];