1test_that("Can't update units", {
2  x <- hms(minutes = 3)
3  expect_equal(units(x), "secs")
4  expect_warning(units(x) <- "mins", "always uses seconds")
5  expect_equal(units(x), "secs")
6  expect_warning(units(x) <- "secs", NA)
7  expect_equal(units(x), "secs")
8})
9