You can define background tasks to be run *after* returning a response.

This is useful for operations that need to happen after a request, but that the client doesn't really have to be waiting for the operation to complete before receiving the response.

This includes, for example:

* Email notifications sent after performing an action:

   * This was misleading for tracing because it was too early.
   */
  open fun responseHeadersStart(call: Call) {
  }

  /**
   * Invoked immediately after receiving response headers.
   *
   * This method is always invoked after [responseHeadersStart].
   *
   * @param response the response received over the network. It is an error to access the body of
   *     this response.

        final ResourceHandler resource_handler = new ResourceHandler();
        resource_handler.setWelcomeFiles(new String[] { "index.html" });
        resource_handler.setResourceBase(docRoot.getAbsolutePath());
        Log.info("serving " + resource_handler.getBaseResource());
        final HandlerList handlers = new HandlerList();
        handlers.setHandlers(new Handler[] { resource_handler, new DefaultHandler() });
        server.setHandler(handlers);
    }

        // Tree handle is released after close
        verify(tree, atLeastOnce()).release();
    }

    @Test
    @DisplayName("open(): server returns NO_SUCH_FILE after receiving response -> iterator empty, closed")
    void openHandlesNoSuchFileGracefully() throws Exception {
        when(tree.send(any(Trans2FindFirst2.class), any(Trans2FindFirst2Response.class))).thenAnswer((InvocationOnMock inv) -> {

            region.close();
            totalReleased.incrementAndGet();
        }
    }

    /**
     * Get a receive region from the pool or allocate a new one
     *
     * @return memory region for receiving
     * @throws IOException if allocation fails
     */
    public RdmaMemoryRegion getReceiveRegion() throws IOException {
        RdmaMemoryRegion region = availableReceiveRegions.poll();
        if (region != null) {

CAREFUL: When utilizing two-way communication, it is important to ensure that the remote handler is not blocked on a send.
If the remote handler is blocked on a send, and the client is trying to send without the remote receiving,
the operation would become deadlocked if the channels are full.

### Typed handlers

Typed handlers are handlers that have a specific type for the request and response payloads.

```go

Just keep in mind that when you read "server" in general, it could refer to one of those two things.

When referring to the remote machine, it's common to call it **server**, but also **machine**, **VM** (virtual machine), **node**. Those all refer to some type of remote machine, normally running Linux, where you run programs.

copyrighted by the Free Software Foundation, write to the Free
Software Foundation; we sometimes make exceptions for this.  Our
decision will be guided by the two goals of preserving the free status
of all derivatives of our free software and of promoting the sharing
and reuse of software generally.

                            NO WARRANTY

 * <p>
 * A consumer POM is a simplified version of a project's POM that is published for consumption by other projects.
 * It removes build-specific information and internal details while preserving essential information like
 * dependencies, repositories, and distribution management.
 * <p>
 * This builder applies two orthogonal transformations:
 * <ul>

controlled by the [`tarinsecurepath` setting](/pkg/archive/tar/#Reader.Next)
and the [`zipinsecurepath` setting](/pkg/archive/zip/#NewReader).
These default to `tarinsecurepath=1` and `zipinsecurepath=1`,
preserving the behavior of earlier versions of Go.
A future version of Go may change the defaults to
`tarinsecurepath=0` and `zipinsecurepath=0`.

Go 1.20 introduced automatic seeding of the