Merge branch 'hotfix/remove_print_r'
Merge branch 'release/v0.3.1'
Merge branch 'release/v0.3.2'
Fix undefined
Fix exception of new line comment
Fix spelling typo
Merge branch 'release/v0.4.0'
Merge branch 'master' into develop

* master:
  Fix spelling typo
  Fix exception of new line comment
  Fix undefined