"ab".remove_suffix("c")

# output:
stdin:1:20
  ╷
1 │ "ab".remove_suffix("c")
  ╵                    ^~~
Error: Cannot remove this suffix. "ab" does not end with "c".

stdin:1:19
  ╷
1 │ "ab".remove_suffix("c")
  ╵                   ^
In call to method 'String.remove_suffix'.