How to get the story point values using server side API ?

Hello team

I want to get the story point values of a workitem story using server side API.
Below is the code which i used (referred from
 https://rsjazz.wordpress.com/2012/08/20/manipulationg-work-item-enumeration-values/ ).
please let me know where I have gone wrong ?

if(attribute!=null && child.hasAttribute(attribute)){
            Object objval = child.getValue(attribute);

            if (objval instanceof Identifier) {
                Identifier literalID = (Identifier) objval;
                Notifications.addWarning("story point value  '" +  "'. check here ");
                ILiteral literal = getLiteralbyID(literalID, attribute);
                String displayValue = literal.getName();
    }

private static  ILiteral getLiteralbyID(Identifier findLliteralID, IAttribute attribute) throws TeamRepositoryException {

     IEnumeration enumeration = fWorkItemCommon.resolveEnumeration(attribute, null);
         List literals = enumeration.getEnumerationLiterals();
        for (Iterator iterator = literals.iterator(); iterator.hasNext();) {
            ILiteral iLiteral = (ILiteral) iterator.next();
            if (iLiteral.getIdentifier2().equals(findLliteralID)) {
                return iLiteral;
            }
        }
        return null;
    }