Address comments

packages/apollo-engine-reporting/src/agent.ts

@@ -404,13 +404,6 @@ export interface AddTraceArgs {
  document?: DocumentNode;
  logger: Logger;
 }
-
-interface TraceCacheKey {
- statsReportKey: string;
- statsBucket: number;
- endsAtMinute: number;
-}
-
 const serviceHeaderDefaults = {
  hostname: os.hostname(),
  agentVersion: `apollo-engine-reporting@${require('../package.json').version}`,
@@ -447,11 +440,7 @@ class StatsMap {
  >();
 
  public toArray(): IContextualizedStats[] {
- const statsWithContext = new Array<IContextualizedStats>();
- for (const statWithContext of this.map.values()) {
- statsWithContext.push(statWithContext);
- }
- return statsWithContext;
+ return Array.from(this.map.values());
  }
 
  public addTrace(trace: Trace) {
@@ -681,9 +670,7 @@ export class EngineReportingAgent<TContext = any> {
  if (!report.tracesPerQuery.hasOwnProperty(statsReportKey)) {
  report.tracesPerQuery[statsReportKey] = new TracesAndStats();
  (report.tracesPerQuery[statsReportKey] as any).encodedTraces = [];
- (report.tracesPerQuery[
- statsReportKey
- ] as any).statsWithContext = new StatsMap();
+ report.tracesPerQuery[statsReportKey].statsWithContext = new StatsMap();
  }
 
  const traceCacheKey = JSON.stringify({