syntax_data: {"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"Span"}]}
source_snippet:         Span { lo_or_index: lo, len_with_tag_or_marker: len, ctxt_or_parent_or_marker: ctxt }
context_before:     fn span(lo: u32, len: u16, ctxt: u16) -> Span {
context_after:     }