Add explicit control of padding to the Builder API.

[codecov-commenter]

Codecov Report

Attention: 13 lines in your changes are missing coverage. Please review.

Comparison is base (003619b) 81.07% compared to head (0a257d6) 81.01%.

Files	Patch %	Lines
src/builder.rs	64.86%	13 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #403 +/- ## ========================================== - Coverage 81.07% 81.01% -0.07% ========================================== Files 31 31 Lines 3112 3123 +11 ========================================== + Hits 2523 2530 +7 - Misses 589 593 +4 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.