func signV4TrimAll(input string) string {
	// Compress adjacent spaces (a space is determined by
	// unicode.IsSpace() internally here) to one space and return
	return strings.Join(strings.Fields(input), " ")
}

// checkMetaHeaders will check if the metadata from header/url is the same with the one from signed headers
func checkMetaHeaders(signedHeadersMap http.Header, r *http.Request) APIErrorCode {

// See the License for the specific language governing permissions and
// limitations under the License.

package metrics

import (
	"context"
	"errors"
	"fmt"
	"io"
	"strings"
	"text/tabwriter"
	"time"

	"github.com/hashicorp/go-multierror"
	"github.com/prometheus/client_golang/api"
	promv1 "github.com/prometheus/client_golang/api/prometheus/v1"
	"github.com/prometheus/common/model"

				(len(sparseMap)%2 == 1 && key != paxGNUSparseNumBytes) ||
				strings.Contains(value, ",") {
				return nil, ErrHeader
			}
			sparseMap = append(sparseMap, value)
		default:
			paxHdrs[key] = value
		}
	}
	if len(sparseMap) > 0 {
		paxHdrs[paxGNUSparseMap] = strings.Join(sparseMap, ",")
	}
	return paxHdrs, nil
}

    assertNull(Strings.emptyToNull(null));
    assertNull(Strings.emptyToNull(""));
    assertEquals("a", Strings.emptyToNull("a"));
  }

  public void testIsNullOrEmpty() {
    assertTrue(Strings.isNullOrEmpty(null));
    assertTrue(Strings.isNullOrEmpty(""));
    assertFalse(Strings.isNullOrEmpty("a"));
  }

  public void testPadStart_noPadding() {
    assertSame("", Strings.padStart("", 0, '-'));

    // Less than 65,536 bytes, because we binary search on a 14-bit index with a stride of 4 bytes.
    assertThat(compactTable.ranges.length).isLessThan((1 shl 14) * 4)

    // Less than 16,384 chars, because we index on a 14-bit index in the ranges table.
    assertThat(compactTable.mappings.length).isLessThan(1 shl 14)

    // Confirm the data strings are ASCII.
    for (dataString in listOf<String>(compactTable.sections, compactTable.ranges)) {

import com.google.common.annotations.GwtCompatible;
import java.nio.charset.StandardCharsets;

/**
 * Static methods pertaining to ASCII characters (those in the range of values {@code 0x00} through
 * {@code 0x7F}), and to strings containing such characters.
 *
 * <p>ASCII utilities also exist in other classes of this package:
 *
 * <ul>
 *   <!-- TODO(kevinb): how can we make this not produce a warning when building gwt javadoc? -->

    assertNull(Strings.emptyToNull(null));
    assertNull(Strings.emptyToNull(""));
    assertEquals("a", Strings.emptyToNull("a"));
  }

  public void testIsNullOrEmpty() {
    assertTrue(Strings.isNullOrEmpty(null));
    assertTrue(Strings.isNullOrEmpty(""));
    assertFalse(Strings.isNullOrEmpty("a"));
  }

  public void testPadStart_noPadding() {
    assertSame("", Strings.padStart("", 0, '-'));

		t.Fatalf("Unexpected output for 'istioctl %s'\n got: %q\nwant: %q", strings.Join(c.args, " "), output, c.expectedOutput)
	}

	if c.expectedString != "" && !strings.Contains(output, c.expectedString) {
		t.Fatalf("Output didn't match for '%s %s'\n got %v\nwant: %v", cmd.Name(), strings.Join(c.args, " "), output, c.expectedString)
	}

	if c.wantException {
		if fErr == nil {

			Args:           strings.Split("invalid --browser=false", " "),
			ExpectedRegexp: regexp.MustCompile(`unknown dashboard "invalid"`),
			WantException:  true,
		},
		{ // case 2
			Args:           strings.Split("controlz --browser=false", " "),
			ExpectedRegexp: regexp.MustCompile(".*Error: specify a pod or --selector"),
			WantException:  true,
		},
		{ // case 3

import (
	"fmt"
	"net/url"
	"strings"
)

func isMCPAddr(u *url.URL) bool {
	return strings.HasSuffix(u.Host, ".googleapis.com") || strings.HasSuffix(u.Host, ".googleapis.com:443")
}

func parseMCPAddr(u *url.URL) (*xdsAddr, error) {
	ret := &xdsAddr{host: u.Host}
	if !strings.HasSuffix(ret.host, ":443") {
		ret.host += ":443"
	}
	const projSeg = "/projects/"
	i := strings.Index(u.Path, projSeg)
	if i == -1 {