test_that("median center works", {
  x <- sf::st_sf(geometry = sf::st_sfc(list(sf::st_point(c(1, 1)),
                                            sf::st_point(c(2, 2)),
                                            sf::st_point(c(3, 3)))))
  y <- sf::st_coordinates(x)
  expect_equal(sf::st_coordinates(st_central_point(x)),
               matrix(apply(y, 2, median), ncol = 2,
                      dimnames = list(NULL, c("X", "Y"))))
  expect_equal(nrow(st_central_point(x, method = "median")), 1)
  expect_error(st_central_point(y, method = "median"))
  expect_s3_class(st_central_point(x, method = "median"), c("sf", "data.frame"))
})