[R] Make doc examples less noisy #29173
Description
Run testthat::test_examples() and see all of the output. Some, like write_to_raw, should assign their output so they don't print so much.
Reporter: Neal Richardson / @nealrichardson
Assignee: Nicola Crane / @thisisnic
PRs and other links:
Note: This issue was originally created as ARROW-13519. Please see the migration documentation for further details.