}

            return response;

        } catch (Exception e) {
            throw new IOException("Witness unregister RPC failed", e);
        }
    }

    /**
     * Sends a witness heartbeat.
     *
     * @param request the heartbeat request
     * @return the heartbeat response
     * @throws IOException if the RPC call fails
     */

So, let's review it from that simplified point of view:

* The user types the `username` and `password` in the frontend, and hits `Enter`.
* The frontend (running in the user's browser) sends that `username` and `password` to a specific URL in our API (declared with `tokenUrl="token"`).
* The API checks that `username` and `password`, and responds with a "token" (we haven't implemented any of this yet).

        lenient().when(fh.isValid()).thenReturn(true);
        lenient().when(fh.getTree()).thenReturn(tree);

        // Mock both sends and return response
        when(tree.send(any(TransWaitNamedPipe.class), any(TransWaitNamedPipeResponse.class))).thenAnswer(inv -> inv.getArgument(1));
        when(tree.send(any(TransCallNamedPipe.class), any(TransCallNamedPipeResponse.class))).thenAnswer(inv -> inv.getArgument(1));

That tells the browser to show the integrated prompt for a username and password.

Then, when you type that username and password, the browser sends them in the header automatically.

## Simple HTTP Basic Auth { #simple-http-basic-auth }

* Import `HTTPBasic` and `HTTPBasicCredentials`.
* Create a "`security` scheme" using `HTTPBasic`.

Then, the browser will send an HTTP `OPTIONS` request to the `:80`-backend, and if the backend sends the appropriate headers authorizing the communication from this different origin (`http://localhost:8080`) then the `:8080`-browser will let the JavaScript in the frontend send its request to the `:80`-backend.

To achieve this, the `:80`-backend must have a list of "allowed origins".

  override fun send(text: String): Boolean = send(text.encodeUtf8(), OPCODE_TEXT)

  override fun send(bytes: ByteString): Boolean = send(bytes, OPCODE_BINARY)

  @Synchronized private fun send(
    data: ByteString,
    formatOpcode: Int,
  ): Boolean {
    // Don't send new frames after we've failed or enqueued a close frame.

            }
        }
    }

    /**
     * Monitors active registrations and sends heartbeats.
     */
    private void monitorRegistrations() {
        for (WitnessRegistration registration : registrations.values()) {
            if (registration.getState() == WitnessRegistrationState.REGISTERED) {
                // Send periodic heartbeat
                sendHeartbeat(registration);
            }
        }

                } catch (final IOException ioe) {
                    logger.warn("Failed to send error response. error={}", ioe.getMessage());
                }
            }
        }
    }

    /**
     * Sends a Server-Sent Event (SSE) to the client.
     *
     * @param writer the print writer to write the event to
     * @param event the event name

import okio.Buffer
import okio.ForwardingTimeout
import okio.Sink
import okio.Source
import okio.Timeout

/**
 * A socket connection that can be used to send HTTP/1.1 messages. This class strictly enforces the
 * following lifecycle:
 *
 *  1. [Send request headers][writeRequest].
 *  2. Open a sink to write the request body. Either [known][newKnownLengthSink] or
 *     [chunked][newChunkedSink].

    @Test
    @DisplayName("setLength(): SMB2 path sends Smb2SetInfoRequest")
    void setLength_smb2_sendsSetInfo() throws Exception {
        SmbRandomAccessFile raf = newInstance("rw", true, false, false);
        SmbFileHandleImpl fh = (SmbFileHandleImpl) getField(raf, "handle");
        SmbTreeHandleImpl tree = fh.getTree();
        // do not actually perform network call