The controller for a chart, created on first use. Use it to change the mode
for the whole chart, to list what is on it, or to clear it.
A chart has one, so a later call returns the same controller, with the mode
and baseline it passes applied through setMode and setBaseline. An
attach helper merges a repeated request this way; a controller that owns
state a second owner would fight over (alerts, a replay group) refuses one.
The controller for a chart, created on first use. Use it to change the mode for the whole chart, to list what is on it, or to clear it.
A chart has one, so a later call returns the same controller, with the
modeandbaselineit passes applied throughsetModeandsetBaseline. An attach helper merges a repeated request this way; a controller that owns state a second owner would fight over (alerts, a replay group) refuses one.