215> binary_string:test().
Creation: <<0,1,1,2,3,5,8,13>>
Copy: <<0,1,1,2,3,5,8,13>>
Equal: <<0,1,1,2,3,5,8,13>> = <<0,1,1,2,3,5,8,13>> ? true
Empty: <<0,1,1,2,3,5,8,13>> ? false
Empty: <<>> ? true
Substring: <<0,1,1,2,3,5,8,13>> [3..5] => <<2,3,5>>
Replacement: <<0,42,42,2,3,5,8,13>>
Append: <<0,1,1,2,3,5,8,13,21>>
Join: <<0,1,1,2,3,5,8,13,21,34,55>>