A new chart (sheet.getCharts().add), or a chart given a type, can be any type of Excel's
gallery: the column, bar, line, pie, doughnut, area, scatter, bubble and radar forms, flat or
3-D; the surfaces; and the 2016 types (waterfall, treemap, sunburst, histogram, pareto, box and
whisker, funnel, region map), whose model is made and saved as Excel makes it; every one of
them is drawn but the region map, which is drawn as a placeholder. A series given a type can be any flat type. A new
chart can also be one of the four stock types, made of exactly their series in order
(stockHLC: high, low, close; stockOHLC with the open first; stockVHLC and stockVOHLC
with the volume before them), which no series can be given. The read vocabulary of earlier
versions is accepted too: column for columnClustered, columnPercentStacked for
columnStacked100, scatter for xyscatter.
A kind of the host's own, registered with ChartKinds, is custom:<kind>: the chart is made
as a column chart is, its categories and values on a pair of axes, and laid out and painted by
the kind. IChart.getChartType answers it back.
A chart type, by the names Office Scripts gives them (
ExcelScript.ChartType).