{"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"//"}]}
//  3. Much later, in AST lowering (rustc_ast_lowering), that `FormatArgs` structure will be turned
//     produce diagnostics, and turn the whole thing into a `FormatArgs` AST node.
//     into the expression of type `core::fmt::Arguments`.