{"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"src.expect_char('=').map_err(|()|"}]}
        src.expect_char('=').map_err(|()| ParseError::expected("expected `=`"))?;
            src.expect_subtree().map_err(|()| ParseError::expected("expected subtree"))?;
        src.expect_char('>').map_err(|()| ParseError::expected("expected `>`"))?;