Improve test for sdk/config

[JacksonTian]

No description provided.

[codecov-io]

Codecov Report

Merging #97 into master will increase coverage by 1.47%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #97      +/-   ##
==========================================
+ Coverage   22.41%   23.89%   +1.47%     
==========================================
  Files          22       22              
  Lines        1169     1172       +3     
==========================================
+ Hits          262      280      +18     
+ Misses        863      848      -15     
  Partials       44       44

Impacted Files	Coverage Δ
sdk/config.go	100% <100%> (+48.38%)	⬆️

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