syntax_data: {"ast_node_type":"function","tokens":[{"end":51,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn from_span(span: Span) -> PartiallyInterned {
context_before:     #[inline]
context_after:         PartiallyInterned { index: span.lo_or_index, ctxt: span.ctxt_or_parent_or_marker }