# Docstring Tests

func main():
    # Docstring tests begin with `>>` and can
    # be used to check that a value is what you
    # expected it to be:

    >> 1 + 1
    = 2

    # If you don't provide an expected value,
    # the expression will just be printed out
    # and not checked:
    >> 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:
    >> 2 + 2
    = ???