I've been working my way through the Ruby Koans and am confused by the "escape clauses and single quoted strings" examples. 

One example shows that I can't really use escape characters in this way, but immediately after, the following example is given:

```
def test_single_quotes_sometimes_interpret_escape_characters
  string = '\\\''
  assert_equal 2, string.size # <-- my answer is correct according to the program
  assert_equal "\\'", string  # <-- my answer is correct according to the program
end

```

This has confused me on two fronts: 

1. Single quotes can sometimes be used with escape characters.
2. Why is the string size `2`, when `assert_equal` is `"\\\'"`? (I personally thought the answer was `"\'"`, which would make more sense with regards to size).