pub fn new(features: Vec<Feature>) -> Self {

        ProtocolEnableRequest(features)

    }

    fn serialize(&self) -> String {

        let features = self

            .0

            .iter()

            .map(|f| f.to_string())

            .collect::<Vec<String>>()

            .join(" ");

        format!("{} {}", Self::COMMAND, features)

    }

    fn parse(parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {

        let mut parts = parts.peekable();

        if parts.peek().is_none() {

            return Err(Self::missing_arguments_error(0));

        }

        let features = parts

            .enumerate()

            .map(|(i, f)| {

                f.parse()

                    .map_err(|_| RequestParserError::SubtypeParserError {

                        argument_index: i.try_into().unwrap_or(u32::MAX),

                        raw_input: f.to_owned(),

                    })

            })

            .collect::<Result<Vec<Feature>, RequestParserError>>()?;

        Ok(ProtocolEnableRequest(features))

    }