[Bugfix] Added NULL check for session_key in KvawareRouter

[vjayarag]

FIX the issue in: #735

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[gemini-code-assist]

Summary of Changes

Hello @vjayarag, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request implements a crucial bug fix within the "KvawareRouter" by adding a "None" check for the "session_key" configuration. This change prevents potential "AttributeError" exceptions that could occur if the "session_key" was not set, thereby enhancing the stability and reliability of the routing logic when handling session-aware requests.

Highlights

• Robustness Improvement: Introduced a "None" check for "self.session_key" in "KvawareRouter" to prevent "AttributeError" when attempting to access request headers with an unconfigured session key.
• Bug Fix: Addresses an issue where the router could fail if "self.session_key" was "None", ensuring stable operation as reported in issue bug: session_key args has no null check #735.

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[gemini-code-assist]

Code Review

This pull request correctly fixes a potential AttributeError that could occur in KvawareRouter if session_key is None. The added check effectively prevents this issue. My feedback includes a suggestion to make the code more concise while preserving the same logic, which can improve readability.

[ruizhang0101]

Hi, I think this issue has been fixed, can you check that?