# Assertions

func main()
    # Assertions can be used to check that a
    # value is what you expect it to be:

    assert 1 + 1 == 2

    # For debugging purposes, you can use `>>`
    # to print out a value:
    >> 20 + 30

    # If a docstring test's output is different
    # from what was expected, it will print an
    # error message and halt the program.

    # Edit this test so it passes:
    assert 2 + 2 == ???