use std::cell::RefCell;use std::collections::HashSet;use std::sync::OnceLock; use html5ever::Attribute; /// Returns a [`HashSet`] containing the HTML elements that are inline by default.////// [MDN: List of "inline" elements](https://yari-demos.prod.mdn.mozit.cloud/en-US/docs/Web/HTML/Inline_elements)fn inline_elements() -> &'static HashSet<&'static str> {    static INLINE_ELEMENTS: OnceLock<HashSet<&str>> = OnceLock::new();    &INLINE_ELEMENTS.get_or_init(|| {        HashSet::from_iter([            "a", "abbr", "acronym", "audio", "b", "bdi", "bdo", "big", "br", "button", "canvas",            "cite", "code", "data", "datalist", "del", "dfn", "em", "embed", "i", "iframe", "img",            "input", "ins", "kbd", "label", "map", "mark", "meter", "noscript", "object", "output",            "picture", "progress", "q", "ruby", "s", "samp", "script", "select", "slot", "small",            "span", "strong", "sub", "sup", "svg", "template", "textarea", "time", "tt", "u",            "var", "video", "wbr",        ])    })} #[derive(Debug, Clone)]pub struct HtmlElement {    pub(crate) tag: String,    pub(crate) attrs: RefCell<Vec<Attribute>>,} impl HtmlElement {    /// Returns whether this [`HtmlElement`] is an inline element.    pub fn is_inline(&self) -> bool {        inline_elements().contains(self.tag.as_str())    }     /// Returns the attribute with the specified name.    pub fn attr(&self, name: &str) -> Option<String> {        self.attrs            .borrow()            .iter()            .find(|attr| attr.name.local.to_string() == name)            .map(|attr| attr.value.to_string())    }     /// Returns the list of classes on this [`HtmlElement`].    pub fn classes(&self) -> Vec<String> {        self.attrs            .borrow()            .iter()            .find(|attr| attr.name.local.to_string() == "class")            .map(|attr| {                attr.value                    .split(' ')                    .map(|class| class.trim().to_string())                    .collect::<Vec<_>>()            })            .unwrap_or_default()    }     /// Returns whether this [`HtmlElement`] has the specified class.    pub fn has_class(&self, class: &str) -> bool {        self.has_any_classes(&[class])    }     /// Returns whether this [`HtmlElement`] has any of the specified classes.    pub fn has_any_classes(&self, classes: &[&str]) -> bool {        self.attrs.borrow().iter().any(|attr| {            attr.name.local.to_string() == "class"                && attr                    .value                    .split(' ')                    .any(|class| classes.contains(&class.trim()))        })    }}