Method subscribe

src/grapher/datasource.ts:81–84

(graphId: string, callback: (point: GraphPoint) => void)

    }

    public subscribe(graphId: string, callback: (point: GraphPoint) => void) {
        if (!this.subscriptions[graphId]) { this.subscriptions[graphId] = []; }
        this.subscriptions[graphId].push(callback);
    }
}