fix: do not handle empty attributes

[alexander-akait]

This PR contains a:

• bugfix
• new feature
• code refactor
• test update
• typo fix
• metadata update

Motivation / Use-Case

fixes #191

Breaking Changes

No

Additional Info

No

[codecov]

Codecov Report

Merging #210 into master will increase coverage by 0.04%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #210      +/-   ##
==========================================
+ Coverage   95.23%   95.28%   +0.04%     
==========================================
  Files           5        5              
  Lines         105      106       +1     
  Branches       20       21       +1     
==========================================
+ Hits          100      101       +1     
  Misses          4        4              
  Partials        1        1

Impacted Files	Coverage Δ
src/index.js	98.14% <100%> (+0.03%)	⬆️

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