{"ast_node_type":"function","tokens":[{"end":78,"kind":"keyword","start":0,"text":"pub"}]}
    pub fn hir_get_if_cause(self, hir_id: HirId) -> Option<&'tcx Expr<'tcx>> {
    /// expression needing to be unit.
        for (_, node) in self.hir_parent_iter(hir_id) {