add tests for getShuttleById

test/repositories/ApiBasedRepositoryTests.test.ts

@@ -331,3 +331,17 @@ describe("updateEtasForSystemIfTTL", () => {
   });
 });
 
+describe("getShuttleById", () => {
+  test("getShuttleById returns null if unseeded cache", async () => {
+
+  });
+
+  test("getShuttleById returns old data if not expired", async () => {
+
+  });
+
+  test("getShuttleById returns fresh data if expired", async () => {
+
+  });
+});
+