Returns series category.
This method returns current series category, which can be one of the following enumerated values:
- BCGPChartLine,
- BCGPChartPie,
- BCGPChartPie3D,
- BCGPChartPyramid,
- BCGPChartPyramid3D,
- BCGPChartFunnel,
- BCGPChartFunnel3D,
- BCGPChartColumn,
- BCGPChartBar,
- BCGPChartHistogram,
- BCGPChartArea,
- BCGPChartStock,
- BCGPChartBubble,
- BCGPChartLongData,
- BCGPChartHistoricalLine,
- BCGPChartPolar,
- BCGPChartDoughnut,
- BCGPChartDoughnut3D,
- BCGPChartTorus3D,
- BCGPChartTernary,
- BCGPChartColumn3D,
- BCGPChartBar3D,
- BCGPChartLine3D,
- BCGPChartArea3D,
- BCGPChartSurface3D,
- BCGPChartDoughnutNested,
