{"ast_node_type":"other","tokens":[{"end":42,"kind":"keyword","start":0,"text":"TokenTree::token_joint_hidden("}]}
            TokenTree::token_joint_hidden(
            TokenTree::token_alone(token::Ident(kw::Fn, IdentIsRaw::No), sp(0, 2)),
                token::Ident(Symbol::intern("a"), IdentIsRaw::No),