When you declare a default value for non-path parameters (for now, we have only seen query parameters), then it is not required.

If you don't want to add a specific value but just make it optional, set the default as `None`.

But when you want to make a query parameter required, you can just not declare any default value:

```Python hl_lines="6-7"
{!../../docs_src/query_params/tutorial005.py!}
```

	cred, seedSignature, region, seedDate, errCode := calculateSeedSignature(req, trailer)
	if errCode != ErrNone {
		return nil, errCode
	}

	if trailer {
		// Discard anything unsigned.
		req.Trailer = make(http.Header)
		trailers := req.Header.Values(awsTrailerHeader)
		for _, key := range trailers {
			req.Trailer.Add(key, "")
		}
	} else {
		req.Trailer = nil
	}
	return &s3ChunkedReader{

		"SecretKey": ui.Credentials.SecretKey,
	}
	if ui.Credentials.IsTemp() {
		copts["SessionToken"] = ui.Credentials.SessionToken
	}

	return &ssh.Permissions{
		CriticalOptions: copts,
		Extensions:      make(map[string]string),
	}, nil
}

func processLDAPAuthentication(key ssh.PublicKey, pass []byte, user string) (perms *ssh.Permissions, err error) {
	var lookupResult *xldap.DNSearchResult
	var targetGroups []string

				OrgNum:    req.Num,
				OrgString: req.String,
				Embedded:  *req,
			}, nil
		}))
		errFatal(err)
	}
	const payloadSize = 512
	rng := rand.New(rand.NewSource(time.Now().UnixNano()))
	payload := make([]byte, payloadSize)
	_, err = rng.Read(payload)
	errFatal(err)

	// Wait for all to connect
	// Parallel writes per server.
	b.Run("bytes", func(b *testing.B) {
		for par := 1; par <= 32; par *= 2 {

	"log"
)

func bytesToPrivateKey(priv []byte) (*rsa.PrivateKey, error) {
	// Try PEM
	if block, _ := pem.Decode(priv); block != nil {
		return x509.ParsePKCS1PrivateKey(block.Bytes)
	}
	// Try base 64
	dst := make([]byte, base64.StdEncoding.DecodedLen(len(priv)))
	if n, err := base64.StdEncoding.Decode(dst, priv); err == nil {
		return x509.ParsePKCS1PrivateKey(dst[:n])
	}
	// Try Raw, return error

Google as part of the Go project.

Google hereby grants to You a perpetual, worldwide, non-exclusive,
no-charge, royalty-free, irrevocable (except as stated in this section)
patent license to make, have made, use, offer to sell, sell, import,
transfer and otherwise run, modify and propagate the contents of this
implementation of Go, where such license applies only to those patent

package com.google.common.collect.testing;

import com.google.common.annotations.GwtIncompatible;
import java.util.Set;

/**
 * Reserializes the sets created by another test set generator.
 *
 * <p>TODO: make CollectionTestSuiteBuilder test reserialized collections
 *
 * @author Jesse Wilson
 */
@GwtIncompatible
public class ReserializingTestSetGenerator<E> extends ReserializingTestCollectionGenerator<E>

        return "https://golang.org/cl/" + t;
    }

    var match = commitRE.exec(t);
    if (match) {
        return "https://golang.org/change/" + match[1];
    }

    if (pkgRE.test(t)) {
        // TODO: make this smarter, using a list of packages + substring matches.
        // Get the list from godoc itself in JSON format?
        return "https://golang.org/pkg/" + t;
    }

    return null;

  # non-interactive shells as well.
  shopt -s expand_aliases
else
  echo '==TFCI==: Error: Cannot find path to grealpath or gstat'
  echo 'TF CI scripts require GNU core utilties to be installed. Please make'
  echo 'sure they are present on your system and try again.'
  exit 1
fi

# "TFCI_MACOS_BAZEL_TEST_DIR_PATH" specifies the directory that Bazel should use

			if err != nil {
				err = msgp.WrapError(err, "Parts")
				return
			}
			if cap(z.Parts) >= int(zb0002) {
				z.Parts = (z.Parts)[:zb0002]
			} else {
				z.Parts = make([]CompletePart, zb0002)
			}
			for za0001 := range z.Parts {
				bts, err = z.Parts[za0001].UnmarshalMsg(bts)
				if err != nil {
					err = msgp.WrapError(err, "Parts", za0001)
					return
				}
			}