anchor.diff:  
                   , client_shared_secret = ClientSharedSecret
   
  -                , token                = {some, TmpToken}
  +                , token                = {some, Token}
                   , verifier             = {some, Verifier}
                   , callback             = none
                   },
  
positive.code: 
  -spec make_validate_consumer_key(oauth1_credentials:id(client)) ->
      request_validator(any()).
  make_validate_consumer_key(ConsumerKey) ->
      fun (#request_validation_state{}=State1) ->
          case oauth1_credentials:fetch(ConsumerKey)
          of  {error, not_found} ->
                  {error, {unauthorized, client_credentials_invalid}}
          ;   {error, _}=Error ->
                  Error
          ;   {ok, ClientCredentials} ->
                  State2 =
                      State1#request_validation_state
                      { creds_client = {some, ClientCredentials}
                      },
                  {ok, State2}
          end
      end.
  
  -spec make_validate_tmp_token(oauth1_credentials:id(tmp)) ->
      request_validator(any()).
  make_validate_tmp_token(TmpTokenID) ->
      fun (#request_validation_state{}=State1) ->
          case oauth1_credentials:fetch(TmpTokenID)
          of  {error, not_found} ->
                  {error, {unauthorized, token_invalid}}
          ;   {ok, TmpToken} ->
                  State2 =
                      State1#request_validation_state
                      { creds_tmp_tok = {some, TmpToken}
                      },
                  {ok, State2}
          end
      end.
  
  
negative.code:     ValidateSignature =
          fun (#request_validation_state
              { creds_client = {some, ClientCredentials}
              , creds_token  = {some, Token}
              , verifier     = {some, Verifier}
              }=State) ->
              ClientSharedSecret =
  