changes

src/app/services/prefetch.service.ts

@@ -0,0 +1,15 @@
+import { Injectable } from '@angular/core';
+import { ApiService } from './api.service';
+
+@Injectable({ providedIn: 'root' })
+export class PrefetchService {
+  private prefetched = new Set<number>();
+
+  constructor(private api: ApiService) {}
+
+  prefetchItem(itemID: number): void {
+    if (this.prefetched.has(itemID)) return;
+    this.prefetched.add(itemID);
+    this.api.getItem(itemID).subscribe();
+  }
+}