function cleanData(originalData) {
            return originalData.reduce((acc, d) => {
                d.value = +d[valueLabel];
                d.key = String(d[nameLabel]);

                return [...acc, d];
            }, []);
        }
Cleaning data casting the values and keys to the proper type while keeping
the rest of properties on the data
@param  {StepChartData} originalData Data as provided on the container
@private