anchor.diff:  
   
   %% @doc sign_final_create/2 computes the signature for the previously supplied
  -%% message(s) using the secret key `SK`.
  +%% message(s) using the secret key `SK'.
   %% @end
   -spec sign_final_create(S, SK) -> {ok, binary()} | {error, atom()}
       when S :: sign_state(),
  
positive.code: %%% portable variant of the NaCl library. The C-level API is interchangeable so we can run
  %%% on any of these underlying libraries as seen from the Erlang world. We simply have to
  %%% restrict ourselves to the portion of the code base which is overlapping.</p>
  %%% <p><b>Warning:</b> The cryptographic strength of your implementation is no stronger than
  %%% plaintext cryptography unless you take care in using these primitives correctly. Hence,
  %%% implementors should use these primitives with that in mind.</p>
  %%% <p><b>Note:</b> All functions will fail with a `badarg' error if given incorrect
  %%% parameters.</p>
  %%% @end.
  
negative.code: 
  %% @doc sign_final_verify/3 verify a chunked signature
  %%
  %% Verifies that `SIG' is a valid signature for the message whose content has
  %% been previously supplied using `sign_update/2' using the public key `PK.'
  %% @end
  -spec sign_final_verify(S, SIG, PK) -> boolean()
      when S :: sign_state(),
  