Configuration for a fan chart.
Required when chartType is 'percentile_band'.
A range <Area> says nothing about which quantiles its edges are: the same
area draws a min-max envelope and a 95% interval. So the levels are
declared, one entry per band, and must nest -- each band strictly inside the
next wider one -- as the co-located maidr declaration's bands must.
Configuration for a fan chart. Required when
chartTypeis'percentile_band'.A range
<Area>says nothing about which quantiles its edges are: the same area draws a min-max envelope and a 95% interval. So the levels are declared, one entry per band, and must nest -- each band strictly inside the next wider one -- as the co-locatedmaidrdeclaration'sbandsmust.