public String getValue(String entityName) {
        notNull(entityName, "Entity name");
        final T entity = get(entityName);
        if(entity == null) {
            return null;
        }
        return entity.getValue();
    }
public String getValue(String entityName) {
        notNull(entityName, "Entity name");
        final T entity = get(entityName);
        if(entity == null) {
            return null;
        }
        return entity.getValue();
    }
public String getValue ( String entityName ) { notNull ( entityName , "Entity name" ) ; final T entity = get ( entityName ) ; if ( entity == null ) { return null ; } return entity . getValue ( ) ; }
Get a single entity value with the supplied name. If there are several headers match the <code>headerName</code> then
the last one is returned.

@param entityName The name of the header to find
@return The found entity value or <code>null</code> if no header was found.
Get a single entity value with the supplied name . If there are several headers match the <code > headerName< / code > then the last one is returned .