def verified(signed_message, purpose: nil, **)
      if valid_message?(signed_message)
        begin
          data = signed_message.split("--")[0]
          message = Messages::Metadata.verify(decode(data), purpose)
          @serializer.load(message) if message
        rescue ArgumentError => argument_error
          return if argument_error.message.include?("invalid base64")
          raise
        end
      end
    end
def verified(signed_message, purpose: nil, **)
      if valid_message?(signed_message)
        begin
          data = signed_message.split("--")[0]
          message = Messages::Metadata.verify(decode(data), purpose)
          @serializer.load(message) if message
        rescue ArgumentError => argument_error
          return if argument_error.message.include?("invalid base64")
          raise
        end
      end
    end
Decodes the signed message using the +MessageVerifier+'s secret.

   verifier = ActiveSupport::MessageVerifier.new 's3Krit'

   signed_message = verifier.generate 'a private message'
   verifier.verified(signed_message) # => 'a private message'

 Returns +nil+ if the message was not signed with the same secret.

   other_verifier = ActiveSupport::MessageVerifier.new 'd1ff3r3nt-s3Krit'
   other_verifier.verified(signed_message) # => nil

 Returns +nil+ if the message is not Base64-encoded.

   invalid_message = "f--46a0120593880c733a53b6dad75b42ddc1c8996d"
   verifier.verified(invalid_message) # => nil

 Raises any error raised while decoding the signed message.

   incompatible_message = "test--dad7b06c94abba8d46a15fafaef56c327665d5ff"
   verifier.verified(incompatible_message) # => TypeError: incompatible marshal file format