///

By using a `with` block, we make sure that the file-like object is closed after the generator function (the function with `yield`) is done. So, after it finishes sending the response.

It wouldn't be that important in this specific example because it's a fake in-memory file (with `io.BytesIO`), but with a real file, it would be important to make sure the file is closed after the work with it is done.

### Files and Async { #files-and-async }

        }

        /** The return value of the operation */
        public int retval;
        /** The handle to be closed */
        public rpc.policy_handle handle;

        /**
         * Constructs a SamrCloseHandle request.
         *
         * @param handle The policy handle to close
         */
        public SamrCloseHandle(final rpc.policy_handle handle) {
            this.handle = handle;
        }

        }

        /** The return value of the operation */
        public int retval;
        /** The handle to be closed */
        public rpc.policy_handle handle;

        /**
         * Constructs a SamrCloseHandle request.
         *
         * @param handle The policy handle to close
         */
        public SamrCloseHandle(final rpc.policy_handle handle) {
            this.handle = handle;
        }

                                                        </h4>
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	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	resp, err := k.client.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	var accessToken Token
	if err = json.NewDecoder(resp.Body).Decode(&accessToken); err != nil {
		return err
	}

	k.Lock()
	k.accessToken = accessToken
	k.Unlock()
	return nil
}

            new Thread(() -> {
                try {
                    CloseableUtil.closeQuietly(process.getInputStream());
                } catch (final Exception e) {
                    logger.warn("Could not close a process input stream.", e);
                } finally {
                    latch.countDown();
                }
            }, "ProcessCloser-input-" + sessionId).start();
            new Thread(() -> {

	if err != nil {
		return nil, err
	}

	if err = lockFile(syscall.Handle(f.Fd()), lockType); err != nil {
		f.Close()
		return nil, err
	}

	st, err := os.Stat(path)
	if err != nil {
		f.Close()
		return nil, err
	}

	if st.IsDir() {
		f.Close()
		return nil, &os.PathError{
			Op:   "open",
			Path: path,
			Err:  syscall.EISDIR,
		}
	}

		if err != nil {
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}
		defer gr.Close()
		rc, err = file.Open(gr)
		if err != nil {
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}
	} else {
		rc = io.NopCloser(bytes.NewReader([]byte{}))
	}

	defer rc.Close()

	if err = setObjectHeaders(ctx, w, fileObjInfo, nil, opts); err != nil {

async def get_db():
    db = DBSession()
    try:
        yield db
    finally:

            log.warn("Error during witness client shutdown", e);
        }
        
        // Shutdown scheduler
        scheduler.shutdown();
        
        // Close RPC client
        if (rpcClient != null) {
            rpcClient.close();
        }
    }
}
```

### 4.4 Witness RPC Client
```java
package jcifs.internal.witness;

import jcifs.dcerpc.*;
import jcifs.dcerpc.rpc.*;