test(document): add plot test

[Yongxuanzhang]

complete the test of document.plot()

[codecov]

Codecov Report

Merging #2245 (baa3cf5) into master (4fa7af2) will increase coverage by 0.12%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2245      +/-   ##
==========================================
+ Coverage   90.62%   90.75%   +0.12%     
==========================================
  Files         209      209              
  Lines       11311    11311              
==========================================
+ Hits        10251    10265      +14     
+ Misses       1060     1046      -14     

Flag	Coverage Δ
daemon	51.18% <ø> (ø)
jina	91.22% <ø> (+0.13%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
jina/types/document/__init__.py	95.64% <0.00%> (+3.38%)	⬆️

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[github-actions]

Latency summary

Current PR yields:

• 😶 index QPS at 1049, delta to last 3 avg.: +4%
• 🐢🐢 query QPS at 14, delta to last 3 avg.: -7%

Breakdown

Version	Index QPS	Query QPS
current	1049	14
1.0.16	1007	15

Backed by latency-tracking. Further commits will update this comment.