This class supports the following attributes:
Amount of space below the last line.
Space between each column in the legend.
Space between each row in the legend.
Amount of space left of the legend.
Bottom-left corner of the legend. The default location of a legend is the bottom-right end of the chart.
Number of rows in the legend. If the number of plots in a chart is larger than nr_rows, multiple columns are created in the legend.
Amount of space right of the legend.
The value is either None or a tuple. When non-None, a drop-shadow is drawn beneath the object. X-off, and y-off specifies the offset of the shadow relative to the object, and fill specifies the style of the shadow (see Section 16).
Amount of space above the first line.