add a blocking accept method to RateLimiter

pkg/util/throttle_test.go

@@ -60,3 +60,17 @@ func TestOverBurst(t *testing.T) {
 		r.step()
 	}
 }
+
+func TestThrottle(t *testing.T) {
+	r := NewTokenBucketRateLimiter(10, 5)
+
+	// Should consume 5 tokens immediately, then
+	// the remaining 11 should take at least 1 second (0.1s each)
+	expectedFinish := time.Now().Add(time.Second * 1)
+	for i := 0; i < 16; i++ {
+		r.Accept()
+	}
+	if time.Now().Before(expectedFinish) {
+		t.Error("rate limit was not respected, finished too early")
+	}
+}