anchor.diff:  ) ->
       ValidateSignature =
           fun (#request_validation_state
  -            { creds_client = {some, ClientCredentials}
  -            , creds_token  = {some, Token}
  +            { client_creds = {some, ClientCredentials}
  +            , token_final  = {some, Token}
               }=State) ->
               ClientSharedSecret =
                   oauth1_credentials:get_secret(ClientCredentials),
  
positive.code: ) ->
      ValidateSignature =
          fun (#request_validation_state
              { creds_client = {some, ClientCredentials}
              , creds_token  = {some, Token}
              , verifier     = {some, Verifier}
              }=State) ->
              ClientSharedSecret =
  
negative.code:         ;   {{error, not_found}, token}  -> ErrorInvalidToken
          ;   {{error, _}=Error, _}        -> Error
          ;   {{ok, Creds}, client}        -> {ok, UpdateClient(State1, Creds)}
          ;   {{ok, Creds}, tmp}           -> {ok, UpdateTokenTmp(State1, Creds)}
          ;   {{ok, Creds}, token}         -> {ok, UpdateTokenFnl(State1, Creds)}
          end
      end.
  
  