feat(tianmu): mv func from public to protected(#1501)

[zzzz-vincent]

Summary about this PR

Issue Number: close #1501

Tests Check List

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Changelog

• New Feature
• Bug Fix
• Performance Improvement
• Build/Testing/CI/CD
• Documentation
• Not for changelog (changelog entry is not required)

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

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[mergify]

Thanks for the contribution!
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Please review the labels and make any necessary changes.

[Nliver]

You are welcome to contribute to StoneDB. Please sign the CLA file. Note that your git configuration email must be the same as your Github account binding email.

[zzzz-vincent]

You are welcome to contribute to StoneDB. Please sign the CLA file. Note that your git configuration email must be the same as your Github account binding email.

Added and re push. But it seems that this check is based on previous commits. And I am not sure if it is still possible to change that.

[hustjieke]

You are welcome to contribute to StoneDB. Please sign the CLA file. Note that your git configuration email must be the same as your Github account binding email.

Added and re push. But it seems that this check is based on previous commits. And I am not sure if it is still possible to change that.

After signed CLA, wait for a while，there will be some delay.

[Nliver]

You are welcome to contribute to StoneDB. Please sign the CLA file. Note that your git configuration email must be the same as your Github account binding email.

Added and re push. But it seems that this check is based on previous commits. And I am not sure if it is still possible to change that.

If it doesn't work for a long time, I actually recommend shutting down the PR and resubmitting it

[Nliver]

Well, it looks like your CLA process is stuck. I suggest you close this PR. @zzzz-vincent

Then do the following:

1. Check all of your local Git commit email addresses;
2. Confirm whether this email address is the same as your Github binding email address;
3. If they are inconsistent, it is recommended that you modify them to be consistent.