syntax_data: {"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"DesugaringKind::FormatLiteral"}]}
source_snippet:             DesugaringKind::FormatLiteral { source: true } => "format string literal",
context_before:             DesugaringKind::PatTyRange => "pattern type",
context_after:             DesugaringKind::FormatLiteral { source: false } => {