code: async function count(source) {
      var e_33, _a;
      let i = 0;
      try {
          for (var source_4 = __asyncValues(source), source_4_1; source_4_1 = await source_4.next(), !source_4_1.done;) {
              const it = source_4_1.value;
              ++i;
          }
      }
      catch (e_33_1) { e_33 = { error: e_33_1 }; }
      finally {
          try {
              if (source_4_1 && !source_4_1.done && (_a = source_4.return)) await _a.call(source_4);
          }
          finally { if (e_33) throw e_33.error; }
      }
      return i;
  }
docs: Returns a promise of the count of items returned by evaluating the provided iterable