@Override
    public T getRowData(String rowKey) {
        if (rowKeyConverter != null) {
            FacesContext context = FacesContext.getCurrentInstance();
            return rowKeyConverter.getAsObject(context, UIComponent.getCurrentComponent(context), rowKey);
        }

        throw new UnsupportedOperationException(
                getMessage("Provide a Converter via constructor or implement getRowData(String rowKey) in %s"
                        + ", when basic rowKey algorithm is not used [component=%s,view=%s]."));
    }
Loads the data for the given parameters.

@param first the first entry
@param pageSize the page size
@param sortBy a map with all sort information (only relevant for DataTable, not for eg DataView)
@param filterBy a map with all filter information (only relevant for DataTable, not for eg DataView)
@return the data
primefaces/src/main/java/org/primefaces/model/LazyDataModel.java