Type Alias: ChartBodies

type ChartBodies = Record<AlwaysBody, ChartBody> & Partial<Record<PackedBody, ChartBody>> & {
[id: string]: ChartBody | undefined;
};

A chart's bodies, keyed by id. The analytic core (AlwaysBody) is always present and needs no presence check. PackedBody bodies (Chiron) and any opt-in extras requested via ChartOptions.bodies may be absent when the instant is outside their fitted range (see Chart.unavailable), so those accesses are typed ChartBody | undefined and must be guarded.