The recommended way to manage series is to use Chart#add_series
A BubbleSeries defines the x/y position and bubble size of data in the chart
Creates a new BubbleSeries
The bubble size for this series.
The fill color for this series. Red, green, and blue is expressed as sequence of hex digits, RRGGBB. A perceptual gamma of 2.2 is used.
Serializes the object
The x data for this series.
The y data for this series.