Add streams unit test

[saschagrunert]

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

Refers to #293

Which issue(s) this PR fixes:

None

Special notes for your reviewer:

None

Does this PR introduce a user-facing change?

None

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: saschagrunert

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

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Needs approval from an approver in each of these files:

• OWNERS [saschagrunert]

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[codecov-commenter]

Codecov Report

Merging #681 (a4c5af4) into main (21ae04e) will increase coverage by 2.39%.
The diff coverage is 25.64%.

@@            Coverage Diff             @@
##             main     #681      +/-   ##
==========================================
+ Coverage   31.19%   33.58%   +2.39%     
==========================================
  Files          12       13       +1     
  Lines         949     1039      +90     
  Branches      342      381      +39     
==========================================
+ Hits          296      349      +53     
+ Misses        441      427      -14     
- Partials      212      263      +51     

[haircommander]

/lgtm