# test_that("commutation matrix n = 2", {
#    C <- commutation_mat(2)
#
#    m <- matrix(c(1, 0, 0, 0,
#                  0, 0, 1, 0,
#                  0, 1, 0, 0,
#                  0, 0, 0, 1), ncol = 4, byrow = TRUE)
#
#    expect_equal(C, m)
# })
#
# test_that("commutation matrix n = 3", {
#   C <- commutation_mat(3)
#
#   m <- matrix(c(1, 0, 0, 0, 0, 0, 0, 0, 0,
#                 0, 0, 0, 1, 0, 0, 0, 0, 0,
#                 0, 0, 0, 0, 0, 0, 1, 0, 0,
#                 0, 1, 0, 0, 0, 0, 0, 0, 0,
#                 0, 0, 0, 0, 1, 0, 0, 0, 0,
#                 0, 0, 0, 0, 0, 0, 0, 1, 0,
#                 0, 0, 1, 0, 0, 0, 0, 0, 0,
#                 0, 0, 0, 0, 0, 1, 0, 0, 0,
#                 0, 0, 0, 0, 0, 0, 0, 0, 1), ncol = 9, byrow = TRUE)
#
#   expect_equal(C, m)
# })