{"ast_node_type":"function","tokens":[{"end":96,"kind":"keyword","start":0,"text":"pub"}]}
    pub fn fn_decl(&self, inputs: ThinVec<ast::Param>, output: ast::FnRetTy) -> P<ast::FnDecl> {
    // `self` is unused but keep it as method for the convenience use.
        P(ast::FnDecl { inputs, output })