```typescript
/** An append-only log of timestamped events. */
export interface Event {
  name: string;
  timestamp: number;
}

export type EventLog = {
  record(event: { name: string; timestamp: number }): void;
  since(timestamp: number): Event[];
};

export class EventLog implements EventLog {
  #events: Event[] = [];

  /** Append one event. */
  static record(event: { name: string; timestamp: number }): void {
    throw new Error("Not implemented");
  }

  /** Every event at or after the given timestamp, in insertion order. */
  static since(timestamp: number): Event[] {
    return #events.filter((event) => event.timestamp >= timestamp);
  }
}

EventLog.record = (event: { name: string; timestamp: number }) => {
  throw new Error("Not implemented");
};

EventLog.since = (timestamp: number) => {
  const events = #events.filter((event) => event.timestamp >= timestamp);
  return events;
};
```