checkArgument(
        string.length() >= 2, "input string (%s) must have at least 2 characters", string);
    checkArgument(
        string.length() % 2 == 0,
        "input string (%s) must have an even number of characters",
        string);

    byte[] bytes = new byte[string.length() / 2];
    for (int i = 0; i < string.length(); i += 2) {
      int ch1 = decode(string.charAt(i)) << 4;

Davor war der Umgang mit asynchronem Code jedoch deutlich komplexer und schwieriger.

In früheren Versionen von Python hätten Sie Threads oder <a href="https://www.gevent.org/" class="external-link" target="_blank">Gevent</a> verwenden können. Der Code ist jedoch viel komplexer zu verstehen, zu debuggen und nachzuvollziehen.

// that defines two inputs, "concat_dim" and "values" (in that order).
// You must use TF_AddInput() for the first input (since it takes a
// single tensor), and TF_AddInputList() for the second input (since
// it takes a list, even if you were to pass a list with a single
// tensor), as in:
//   TF_OperationDescription* desc = TF_NewOperation(graph, "Concat", "c");
//   TF_Output concat_dim_input = {...};
//   TF_AddInput(desc, concat_dim_input);

	needUSize := f.UncompressedSize == ^uint32(0)
	needCSize := f.CompressedSize == ^uint32(0)
	needHeaderOffset := f.headerOffset == int64(^uint32(0))

	// Best effort to find what we need.
	// Other zip authors might not even follow the basic format,
	// and we'll just ignore the Extra content in that case.
	var modified time.Time
parseExtras:
	for extra := readBuf(f.Extra); len(extra) >= 4; { // need at least tag and size

这种使用 `async` 和 `await` 的风格在语言中相对较新。

但它使处理异步代码变得容易很多。

这种相同的语法（或几乎相同）最近也包含在现代版本的 JavaScript 中（在浏览器和 NodeJS 中）。

但在此之前，处理异步代码非常复杂和困难。

在以前版本的 Python，你可以使用多线程或者 <a href="https://www.gevent.org/" class="external-link" target="_blank">Gevent</a>。但代码的理解、调试和思考都要复杂许多。

在以前版本的 NodeJS / 浏览器 JavaScript 中，你会使用"回调"，因此也可能导致<a href="http://callbackhell.com/" class="external-link" target="_blank">回调地狱</a>。

## 协程

 *
 * Usually a webserver is reachable with multiple identifiers: its IP addresses, registered
 * domain names, and even `localhost` when connecting from the server itself. Each of a web server's
 * names is a distinct URL and they are not interchangeable. For example, even if
 * `http://square.github.io/dagger` and `http://google.github.io/dagger` are served by the same IP
 * address, the two URLs identify different resources.

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License

 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License