}
	testFileMode(t, f, wt.Mode)
	rc, err := f.Open()
	if err != nil {
		t.Fatalf("opening %s: %v", f.Name, err)
	}
	b, err := io.ReadAll(rc)
	if err != nil {
		t.Fatalf("reading %s: %v", f.Name, err)
	}
	err = rc.Close()
	if err != nil {
		t.Fatalf("closing %s: %v", f.Name, err)
	}
	if !bytes.Equal(b, wt.Data) {
		t.Errorf("File contents %q, want %q", b, wt.Data)
	}
}

     */
    protected static class ProcessDestroyer extends TimerTask {

        /** The process to monitor and destroy. */
        private final Process p;

        /** The input stream thread reading process output. */
        private final InputStreamThread ist;

        /** Flag indicating if the destroyer has been executed. */
        private final AtomicBoolean executed = new AtomicBoolean(false);

      stream.defaultWriteObject();
      stream.writeObject(inverse());
    }

    @GwtIncompatible
    @J2ktIncompatible
        @SuppressWarnings("unchecked") // reading data stored by writeObject
    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
      stream.defaultReadObject();

	Name         string         `xml:"-" json:"name,omitempty"`
	Description  string         `xml:"-" json:"description,omitempty"`

	// Deprecated: In favor of Description - when reading credentials from
	// storage the value of this field is placed in the Description field above
	// if the existing Description from storage is empty.
	Comment string `xml:"-" json:"comment,omitempty"`
}

			}
		}
	}
	defer conn.Close()
	if debugPrint {
		fmt.Printf("grid: Upgraded request: %v\n", remoteAddr)
	}

	msg, _, err := wsutil.ReadClientData(conn)
	if err != nil {
		writeErr(fmt.Errorf("reading connect: %w", err))
		return
	}
	if debugPrint {
		fmt.Printf("%s handler: Got message, length %v\n", m.local, len(msg))
	}

	var message message
	_, _, err = message.parse(msg)
	if err != nil {

       * use the `endpoint` field, compareTo() and endpoint(). Additionally, the main implementation
       * of Cut.compareTo checks for belowAll before reading accessing `endpoint` on another Cut
       * instance.
       */
      super("");
    }

    @Override
    Comparable<?> endpoint() {
      throw new IllegalStateException("range unbounded on this side");

* **Intuitive**: Great editor support. <dfn title="also known as auto-complete, autocompletion, IntelliSense">Completion</dfn> everywhere. Less time debugging.
* **Easy**: Designed to be easy to use and learn. Less time reading docs.
* **Short**: Minimize code duplication. Multiple features from each parameter declaration. Fewer bugs.
* **Robust**: Get production-ready code. With automatic interactive documentation.

## 上下文管理器 { #context-managers }

### 什么是“上下文管理器” { #what-are-context-managers }

“上下文管理器”是你可以在 `with` 语句中使用的任意 Python 对象。

例如，[你可以用 `with` 来读取文件](https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files)：

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

在底层，`open("./somefile.txt")` 会创建一个“上下文管理器”对象。

* **Intuitive**: Great editor support. <dfn title="also known as auto-complete, autocompletion, IntelliSense">Completion</dfn> everywhere. Less time debugging.
* **Easy**: Designed to be easy to use and learn. Less time reading docs.
* **Short**: Minimize code duplication. Multiple features from each parameter declaration. Fewer bugs.
* **Robust**: Get production-ready code. With automatic interactive documentation.

    return sb;
  }

  /**
   * Reads all of the lines from a {@link Readable} object. The lines do not include
   * line-termination characters, but do include other leading and trailing whitespace.
   *
   * <p>Does not close the {@code Readable}. If reading files or resources you should use the {@link
   * Files#readLines} and {@link Resources#readLines} methods.
   *