{"ast_node_type":"function","tokens":[{"end":51,"kind":"keyword","start":0,"text":"pub"}]}
    pub fn to_self(&self) -> Option<ExplicitSelf> {
    /// Attempts to cast parameter to `ExplicitSelf`.
        if let PatKind::Ident(BindingMode(ByRef::No, mutbl), ident, _) = self.pat.kind {