syntax_data: {"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"DesugaringKind::FormatLiteral"}]}
source_snippet:             DesugaringKind::FormatLiteral { source: false } => {
context_before:             DesugaringKind::FormatLiteral { source: true } => "format string literal",
context_after:                 "expression that expanded into a format string literal"