use node pool to reduce allocations

[ucwong]

No description provided.

[codecov]

Codecov Report

Merging #1811 (ce37e63) into master (10411d4) will increase coverage by 0.03%.
Report is 380 commits behind head on master.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1811      +/-   ##
==========================================
+ Coverage   52.67%   52.71%   +0.03%     
==========================================
  Files         485      485              
  Lines       60536    60550      +14     
==========================================
+ Hits        31889    31917      +28     
+ Misses      26192    26182      -10     
+ Partials     2455     2451       -4     

Files	Coverage Δ
trie/iterator.go	81.71% <100.00%> (+0.73%)	⬆️

... and 11 files with indirect coverage changes