Add testcase for SelfLink function

[stewart-yu]

What this PR does / why we need it:
Add testcase for SelfLink function.

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer:

Release note:

NONE

[stewart-yu]

/assign @liggitt

[liggitt]

/ok-to-test
/lgtm
/approve no-issue

[k8s-github-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: liggitt, stewart-yu

Associated issue requirement bypassed by: liggitt

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these OWNERS Files:

• pkg/api/OWNERS [liggitt]

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[fejta-bot]

/retest
This bot automatically retries jobs that failed/flaked on approved PRs (send feedback to @fejta).

Review the full test history for this PR.

[k8s-github-robot]

/test all [submit-queue is verifying that this PR is safe to merge]

[k8s-github-robot]

Automatic merge from submit-queue (batch tested with PRs 52461, 55503). If you want to cherry-pick this change to another branch, please follow the instructions here.