test_that("check for identical structures works", {
  expect_true(identical_structure(1, 2))
  expect_true(identical_structure(list(1), list(2)))
  expect_false(identical_structure(list(1), list()))
  x <- structure(1, class = c("a", "b"))
  y <- structure(1, class = c("b", "a"))
  expect_false(identical_structure(x, y))
  x <- list(list(1, 2, "3"))
  y <- list(list(1, 2, 3))
  expect_false(identical_structure(x, y))
  x <- list(1, 2, 3)
  expect_false(identical_structure(x, y))
})