def test_the_shovel_operator_modifies_the_original_string
    original_string = "Hello, "
    hi = original_string
    there = "World"
    hi << there
    assert_equal "Hello, World", original_string

    # THINK ABOUT IT:
    #
    # Ruby programmers tend to favor the shovel operator (<<) over the
    # plus equals operator (+=) when building up strings.  Why?
  end