nl_tokens: Take only the first item in an iterable sequence
pl_tokens: async function first ( iterable ) { var e_13 , _a ; try { for ( var iterable_11 = __asyncValues ( iterable ) , iterable_11_1 ; iterable_11_1 = await iterable_11 . next ( ) , ! iterable_11_1 . done ; ) { const item = iterable_11_1 . value ; return item ; } } catch ( e_13_1 ) { e_13 = { error : e_13_1 } ; } finally { try { if ( iterable_11_1 && ! iterable_11_1 . done && ( _a = iterable_11 . return ) ) await _a . call ( iterable_11 ) ; } finally { if ( e_13 ) throw e_13 . <mask> ; } } return undefined ; }