| 1
2
3
4
5
6
7
8
9
10
11
12
13
14
 | | import { TimestampProvider } from '../types'; |  |   |  | interface PerformanceTimestampProvider extends TimestampProvider { |  |   delegate: TimestampProvider | undefined; |  | } |  |   |  | export const performanceTimestampProvider: PerformanceTimestampProvider = { |  |   now() { |  |     // Use the variable rather than `this` so that the function can be called |  |     // without being bound to the provider. |  |     return (performanceTimestampProvider.delegate || performance).now(); |  |   }, |  |   delegate: undefined, |  | }; | 
 |