pub(crate) fn expect_element_end(&mut self, start: BytesStart) -> Result<BytesEnd<'a>, XmlError> {

    pub(crate) fn expect_element_end(
        &mut self,
        start: BytesStart,
    ) -> Result<BytesEnd<'a>, XmlError> {

                    expected: format!("start tag"),

                    expected: "start tag",

    pub(crate) fn parse_optional_element<T, F>(&mut self, tag: &str, parser: F) -> XmlResult<Option<T>>

    pub(crate) fn parse_optional_element<T, F>(
        &mut self,
        tag: &str,
        parser: F,
    ) -> XmlResult<Option<T>>