syntax_data: {"ast_node_type":"other","tokens":[{"end":52,"kind":"keyword","start":0,"text":"(index,"}]}
source_snippet:             (index, BASE_LEN_INTERNED_MARKER, ctxt);
context_before:         let (lo_or_index, len_with_tag_or_marker, ctxt_or_parent_or_marker) =
context_after:         Span { lo_or_index, len_with_tag_or_marker, ctxt_or_parent_or_marker }