Fix typo in blocks(...) docstring

[mtfishman]

Fixes #447.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.64%. Comparing base (4059149) to head (a142020).
Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #468   +/-   ##
=======================================
  Coverage   93.64%   93.64%           
=======================================
  Files          19       19           
  Lines        1667     1668    +1     
=======================================
+ Hits         1561     1562    +1     
  Misses        106      106           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.