fake client gives error using CreateToken operation for ServiceAccounts

Question

I have the below code in a test function

import (
      "k8s.io/client-go/kubernetes/fake"
)
 // Mock Kubernetes client
k8sClient := fake.NewClientset()

// Mock service account
serviceAccountName := "test-service-account"
namespace := "test-namespace"
roleArn := "arn:aws:iam::123456789012:role/test-role"
tokenAudience := "sts.amazonaws.com"

// Create a mock service account object with annotations
mockSA := &corev1.ServiceAccount{
    TypeMeta: metav1.TypeMeta{
        Kind:       "ServiceAccount",
        APIVersion: "v1",
    },
    ObjectMeta: metav1.ObjectMeta{
        Name:      serviceAccountName,
        Namespace: namespace,
        Annotations: map[string]string{
            roleARNAnnotation:  roleArn,
            audienceAnnotation: tokenAudience,
        },
    },
}

ctx := context.TODO()

    // Create the mock service account
_, err := k8sClient.CoreV1().ServiceAccounts(namespace).Create(ctx, mockSA, metav1.CreateOptions{})
if err != nil {
    t.Fatalf("failed to create mock service account: %v", err)
}

   // Create the token for service account
token, err := k8sClient.CoreV1().ServiceAccounts(namespace).CreateToken(ctx, serviceAccountName, &authv1.TokenRequest{
    Spec: authv1.TokenRequestSpec{
        Audiences: []string{tokenAudience},
    },
}, metav1.CreateOptions{})
if err != nil {
    t.Fatalf("failed to create service account token: %v", err)
}

When I run this code, I get the error: failed to create service account token: serviceaccounts "" not found. However, I can see that the serviceaccount is created properly by fake client. Not sure why the CreateToken call is refering to a blank serviceaccount. I tried figuring out the issue, but couldn't find the exact root cause.

Anybody experienced this issue before? Any help/suggestions would be appreciated.