pub(crate) fn inside(mut self, parent: impl Into<Pattern>) -> Self {
        let prev = self.parent.replace(parent.into());
        assert!(prev.is_none());
        self
    }
/// Rule applies if element's parent matches.
Rule applies if element's parent matches.
Rule applies if element ' s parent matches .
pub(crate) fn inside(mut self, parent: impl Into<Pattern>) -> Self {
        let prev = self.parent.replace(parent.into());
        assert!(prev.is_none());
        self
    }
pub ( crate ) fn inside ( mut self , parent : impl Into < Pattern > ) -> Self { let prev = self . parent . replace ( parent . into ( ) ) ; assert ! ( prev is_none ( ) ) ; self }
Rule applies if element's parent matches.
Rule applies if element ' s parent matches .
mut self
parent
impl Into<Pattern>