{"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"self.psess.gated_spans.gate(sym::frontmatter,"}]}
        self.psess.gated_spans.gate(sym::frontmatter, frontmatter_span);
        let frontmatter_span = self.mk_sp(frontmatter_opening_pos, self.pos);