fix too many return values(#103)

[pei0804]

for #103

[codecov-io]

Codecov Report

Merging #105 into master will increase coverage by 0.54%.
The diff coverage is 79.22%.

@@            Coverage Diff             @@
##           master     #105      +/-   ##
==========================================
+ Coverage   86.01%   86.56%   +0.54%     
==========================================
  Files           5        5              
  Lines         758      759       +1     
==========================================
+ Hits          652      657       +5     
+ Misses         65       62       -3     
+ Partials       41       40       -1

Impacted Files	Coverage Δ
schema.go	100% <ø> (ø)	⬆️
property.go	80% <76.92%> (+11.25%)	⬆️
parser.go	81.96% <80.39%> (+0.14%)	⬆️

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[easonlin404]

LGTM