// size lets us avoid heap allocations.
	if len(a) > 72 {
		panic("crypto/ecdh: internal error: isLess input too large")
	}
	bufA, bufB := make([]byte, 72), make([]byte, 72)
	for i := range a {
		bufA[i], bufB[i] = a[len(a)-i-1], b[len(b)-i-1]
	}

	// Perform a subtraction with borrow.
	var borrow uint64
	for i := 0; i < len(bufA); i += 8 {

			// since Linux 4.11.
			_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, unix.TCP_FASTOPEN_CONNECT, 1)

			// Enable TCP quick ACK, John Nagle says
			// "Set TCP_QUICKACK. If you find a case where that makes things worse, let me know."
			_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, unix.TCP_QUICKACK, 1)

			/// Enable keep-alive
			{
				_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)

	// This test makes sure /memory/classes/heap/unused:bytes
	// doesn't overflow when allocating and deallocating large
	// objects. It is a regression test for #67019.
	done := make(chan struct{})
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()
		for {
			for range 10 {
				abi.Escape(make([]byte, 1<<20))
			}
			runtime.GC()
			select {

        } else {
          continue; // delete this entry; we already copied an earlier one for the same key
        }
      }
      newEntries[out++] = entry;
    }
    return newEntries;
  }

  /** Makes an entry usable internally by a new ImmutableMap without rereading its contents. */
  static <K, V> ImmutableMapEntry<K, V> makeImmutable(Entry<K, V> entry, K key, V value) {
    boolean reusable =

    {!> ../../../docs_src/query_params_str_validations/tutorial005.py!}
    ```

!!! note
    Having a default value of any type, including `None`, makes the parameter optional (not required).

## Make it required

When we don't need to declare more validations or metadata, we can make the `q` query parameter required just by not declaring a default value, like:

```Python
q: str
```

instead of:

```Python

	}{
		{
			name: "a single plugin makes a Pod schedulable",
			plugins: []*TestPlugin{
				{
					name: "TestPlugin",
					inj:  injectedResult{PostFilterStatus: int(framework.Success)},
				},
			},
			wantStatus: framework.NewStatus(framework.Success, injectReason),
		},
		{
			name: "plugin1 failed to make a Pod schedulable, followed by plugin2 which makes the Pod schedulable",
			plugins: []*TestPlugin{

   * loader of that class from being garbage-collected even if there is a {@link SecurityManager}.
   * The {@link SecurityManager} environment makes such leaks more likely because when you create a
   * {@link URLClassLoader} with a {@link SecurityManager}, the creating code's {@link
   * java.security.AccessControlContext} is captured, and that references the creating code's {@link

    * Tell me how you use FastAPI (I love to hear that).
    * Hear when I make announcements or release new tools.
    * You can also <a href="https://twitter.com/fastapi" class="external-link" target="_blank">follow @fastapi on Twitter</a> (a separate account).
* <a href="https://www.linkedin.com/in/tiangolo/" class="external-link" target="_blank">Follow me on **LinkedIn**</a>.
    * Hear when I make announcements or release new tools (although I use Twitter more often 🤷‍♂).

		ptyp.index = tp.index

		return ptyp
	}

	return f(x.typ)
}

// makeSig makes a signature for the given argument and result types.
// Default types are used for untyped arguments, and res may be nil.
func makeSig(res Type, args ...Type) *Signature {
	list := make([]*Var, len(args))
	for i, param := range args {
		list[i] = NewVar(nopos, nil, "", Default(param))
	}

      }
      group.self += (place.Pos == stack.Sources.length-1) ? stack.Value : 0;
      group.places.push(place);
    }

    // Order by decreasing cost (makes it easier to spot heavy functions).
    // Though alphabetical ordering is a potential alternative that will make
    // profile comparisons easier.
    groups.sort(function(a, b) {
      return (b.sumpos + b.sumneg) - (a.sumpos + a.sumneg);
    });

    return groups;