### Creating the `Settings` only once with `lru_cache` { #creating-the-settings-only-once-with-lru-cache }

Reading a file from disk is normally a costly (slow) operation, so you probably want to do it only once and then reuse the same settings object, instead of reading it for each request.

But every time we do:

```Python
Settings()
```

      return Maps.keyIterator(entrySet().iterator());
    }
  }

  @LazyInit private transient @Nullable Set<V> valueSet;

  @Override
  public Set<V> values() {
    /*
     * We can almost reuse the inverse's keySet, except we have to fix the
     * iteration order so that it is consistent with the forward map.
     */
    Set<V> result = valueSet;
    return (result == null) ? valueSet = new ValueSet() : result;

	if err != nil {
		return nil, err
	}
	cl.subroute = &c.subID
	return cl, nil
}

// Request allows to do a single remote request.
// 'req' will not be used after the call and caller can reuse.
// If no deadline is set on ctx, a 1-minute deadline will be added.
func (c *Connection) Request(ctx context.Context, h HandlerID, req []byte) ([]byte, error) {
	if !h.valid() {
		return nil, ErrUnknownHandler
	}

      InternetDomainName domain = InternetDomainName.from(inputName);

      /*
       * We would ordinarily use constants for the expected results, but
       * doing it by derivation allows us to reuse the test case definitions
       * used in other tests.
       */

      String expectedName = Ascii.toLowerCase(inputName);
      expectedName = expectedName.replaceAll("[\u3002\uFF0E\uFF61]", ".");

        if (th != null) {
            this.treeHandle = null;

            // Optimization: For non-strict lifecycle, delay tree handle closure
            // to allow connection reuse for subsequent operations
            if (this.transportContext.getConfig().isStrictResourceLifecycle()) {
                th.close();
            } else {

That way, in many cases you can learn about containers and Docker and reuse that knowledge with many different tools and components.

     * again and get a more complete representation of the same object; but properties cannot be
     * removed, so this only allows limited reuse of the helper instance. The helper allows
     * duplication of properties (multiple name/value pairs with the same name can be added).
     */
    @Override
    public String toString() {

	"encoding/json"
	"errors"
	"math"
	"net/url"
	"sort"
	"strings"
	"sync"

	"github.com/minio/minio/internal/bpool"
	"github.com/tinylib/msgp/msgp"
)

// Recycler will override the internal reuse in typed handlers.
// When this is supported, the handler will not do internal pooling of objects,
// call Recycle() when the object is no longer needed.
// The recycler should handle nil pointers.
type Recycler interface {

var supportedKexAlgos = []string{
	kexAlgoCurve25519SHA256, kexAlgoCurve25519SHA256LibSSH,
	// P384 and P521 are not constant-time yet, but since we don't
	// reuse ephemeral keys, using them for ECDH should be OK.
	kexAlgoECDH256, kexAlgoECDH384, kexAlgoECDH521,
	kexAlgoDH14SHA256, kexAlgoDH16SHA512, kexAlgoDH14SHA1,
	kexAlgoDH1SHA1,
}

func removeEmptyPort(host string) string {
	if hasPort(host) {
		return strings.TrimSuffix(host, ":")
	}
	return host
}

// Copied from http.NewRequest but implemented to ensure we reuse `url.URL` instance.
func (c *Client) newRequest(ctx context.Context, method string, u url.URL, body io.Reader) (*http.Request, error) {
	rc, ok := body.(io.ReadCloser)
	if !ok && body != nil {
		rc = io.NopCloser(body)
	}