* @return The data index name.
     */
    public String getDataIndex() {
        return dataIndex;
    }

    /**
     * Sets the data index name.
     * @param dataIndex The data index name.
     */
    public void setDataIndex(final String dataIndex) {
        this.dataIndex = dataIndex;
    }

    /**
     * Returns the filter index name.
     * @return The filter index name.
     */