support default value

[jxnu-liguobin]

No description provided.

[codecov]

Codecov Report

Merging #208 (e80764e) into master (aae4c5c) will increase coverage by 0.08%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #208      +/-   ##
==========================================
+ Coverage   89.14%   89.22%   +0.08%     
==========================================
  Files          50       50              
  Lines         746      752       +6     
  Branches       45       45              
==========================================
+ Hits          665      671       +6     
  Misses         81       81              

Impacted Files	Coverage Δ
.../src/main/scala/org/bitlap/common/MacroCache.scala	100.00% <ø> (ø)
...ain/scala/org/bitlap/common/TransformerMacro.scala	100.00% <100.00%> (ø)