$ git log|head -n1
commit ae85dfd4cc0284679ce21bb662427340fa966666
$ time node run.js >/dev/null

real    0m6.551s
user    0m6.336s
sys     0m0.288s

$ git log|head -n1
commit 9125bf1ec0cf78c77a852e0547a4cc69db7797bf
$ time node run.js>/dev/null

real    0m1.702s
user    0m1.644s
sys     0m0.084s