The above example shows you how to create `Sankey` using built-in Google Charts.

For example:

    ...
    "options" => array(
                "sankey" => array(
                    "node" => array("label" => array(
                        "fontName" => 'Times-Roman',
                        "fontSize" => 14,
                        "color" => '#871b47',
                        "bold" => true,
                        "italic" => true
                    ))
                )
            )