def format_chart(chart):
    """Sets size of chart and fontsize of axis and legend

    Parameters
    ----------
    chart : alt.Chart
        Chart which should be configured

    Returns
    -------
    alt.Chart
        Chart with set size and fontsize
    """
    return chart.properties(
        width=600, height=400).configure_axis(
            labelFontSize=12, titleFontSize=12).configure_legend(
                labelFontSize=12, titleFontSize=12)