fix diff method can not be added to RadixTree

[Stellar1999]

What is the purpose of the change?

try fix issue #15433

Checklist

• Make sure there is a GitHub_issue field for the change.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit-test to verify your logic correction. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Make sure gitHub actions can pass. Why the workflow is failing and how to fix it?

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 47.61905% with 11 lines in your changes missing coverage. Please review.

Project coverage is 60.96%. Comparing base (c31164a) to head (1106ae6).

Files with missing lines	Patch %	Lines
...bo/rpc/protocol/tri/rest/mapping/Registration.java	21.42%	5 Missing and 6 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                3.3   #15445      +/-   ##
============================================
+ Coverage     60.90%   60.96%   +0.06%     
+ Complexity    11455    11447       -8     
============================================
  Files          1888     1888              
  Lines         86309    86327      +18     
  Branches      12933    12945      +12     
============================================
+ Hits          52570    52633      +63     
+ Misses        28302    28267      -35     
+ Partials       5437     5427      -10     

Flag	Coverage Δ
integration-tests-java17	33.10% <23.80%> (-0.01%)	⬇️
integration-tests-java8	33.14% <23.80%> (-0.04%)	⬇️
samples-tests-java17	31.43% <0.00%> (-0.04%)	⬇️
samples-tests-java8	29.28% <0.00%> (+<0.01%)	⬆️
unit-tests	58.89% <47.61%> (+0.07%)	⬆️

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[zrlw]

add unit tests from #15433 ?

[Stellar1999]

add unit tests from #15433 ?

Sure,I'll do it later.

[Stellar1999]

@oxsean PTAL

[oxsean]

Please fix the comments.

[Stellar1999]

Please fix the comments.

done.

[oxsean]

LGTM.

[Stellar1999]

@oxsean Please take a look again.I changed Overlap method.