function getMaxLengthLine(...texts) {
            let textSizes = texts.filter(x => !!x)
                .map(x => x.node().getBBox().width);

            return d3Array.max(textSizes);
        }
Figures out the max length of the tooltip lines
@param  {D3Selection[]} texts    List of svg elements of each line
@return {Number}                 Max size of the lines