$key
$key : string
One line on a graph: a name, a unit, and a value per bucket.
Points are parallel to the timeline's buckets rather than sparse, so several series drawn on one chart share an x-axis by construction. A sparse series would need every consumer to reconcile indexes, and the first one to get it wrong would draw a line that is subtly out of step with the others.
The maximum is carried rather than recomputed by the renderer, because an SVG needs it to scale the y-axis before it draws the first point, and a renderer that walked the points twice would disagree with this one about an empty series.
__construct(string $key, string $label, list$points = [], string $unit = '', bool $cumulative = false) : mixed
Constructs a series.
| string | $key | Stable identifier, such as "stored_bytes". |
| string | $label | Operator-facing name. |
| list |
$points | One value per bucket, oldest first. |
| string | $unit | What the values are counted in. |
| bool | $cumulative | TRUE when each point includes everything before it, which changes how a reader reads a fall. |