Added example snippets of the presentation.

example/test/test_linear_transformation.R

@@ -0,0 +1,12 @@
+source("../example.R", chdir=TRUE)
+library(testthat)
+
+test_that("Real numbers are transformed to odd numbers.", {
+  expect_equal(linear_transformation(3) %% 2, 1)
+  expect_equal(linear_transformation(4) %% 2, 1)
+})
+
+test_that("Positive numbers remain positive.", {
+  expect_true(linear_transformation(3) > 0)
+  expect_true(linear_transformation(10) > 0)
+})