private static String getNamesOfElements(Map<String, String> elements, String elementName) {
        int count = 0;
        String result = "";
        for (String name : elements.values()) {
            if (name.equals(elementName)) {
                result += elements.keySet().toArray(new String[] {})[count] + ", ";
            }
            count++;
        }
        if(result.length() == 0){
            return "Scheme doesn`t contain elements of this type.";
        }
        return "Elements: [" + result.substring(0, result.length() - 2) + "]";
    }