{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"self.dcx().emit_err(errors::FrontmatterInvalidOpeningPrecedingWhitespace"}]}
            self.dcx().emit_err(errors::FrontmatterInvalidOpeningPrecedingWhitespace {
            let label_span = self.mk_sp(line_start, frontmatter_opening_pos);
                span,