Update builder.ts - Fix typo

[Damiencastro]

Checklist

• Issue number for this PR: #nnn (required)

•  no corresponding pr
  

• Docs included?: (yes/no; required for all API/functional changes)

•  no docs included
  

• Test units included?: (yes/no; required)

•  no tests, just simple typo fix
  

• In a clean directory, yarn install, yarn test run successfully? (yes/no; required)

•  no
  

Description

Code sample