_, got := IsRequested(test.Header)
		if Requested(test.Header) != got {
			// Test if result matches.
			t.Errorf("Requested mismatch, want %v, got %v", Requested(test.Header), got)
		}
		got = got && S3KMS.IsRequested(test.Header)
		if got != test.Expected {
			t.Errorf("SSE-KMS: Test %d: Wanted %v but got %v", i, test.Expected, got)
		}
	}
	for i, test := range s3IsRequestedTests {
		_, got := IsRequested(test.Header)

			if err != nil && !strings.Contains(err.Error(), tt.wantErr) {
				t.Errorf("parseHexUint(%q) = %v, %v; want error %q", tt.in, got, err, tt.wantErr)
			}
		} else {
			if err != nil || got != tt.want {
				t.Errorf("parseHexUint(%q) = %v, %v; want %v", tt.in, got, err, tt.want)
			}
		}
	}

## Return Type and Data Filtering { #return-type-and-data-filtering }

Let's continue from the previous example. We wanted to **annotate the function with one type**, but we wanted to be able to return from the function something that actually includes **more data**.

	readSetAt               time.Time
	writeDeadline           time.Duration // sets the write deadline on a connection.
	writeSetAt              time.Time
	abortReads, abortWrites atomic.Bool // A deadline was set to indicate caller wanted the conn to time out.
	infReads, infWrites     atomic.Bool
	mu                      sync.Mutex
}

// Unwrap will unwrap the connection and remove the deadline if applied.

			},
			OutCapacity: 1,
			InCapacity:  1,
		}))
	}
	register(local)
	register(remote)
	// Double remote DL
	local.debugMsg(debugAddToDeadline, wantDL)
	defer local.debugMsg(debugAddToDeadline, time.Duration(0))
	remote.debugMsg(debugAddToDeadline, wantDL)
	defer remote.debugMsg(debugAddToDeadline, time.Duration(0))

	testHandler := func(t *testing.T, handler HandlerID) {
		remoteConn := local.Connection(remoteHost)

		const hashLen = 4
		if len(h) < hashLen {
			return nil, nil, fmt.Errorf("want crc len 4, got %v", len(h))
		}
		got := uint32(xxh3.Hash(b[:len(b)-hashLen]))
		want := binary.LittleEndian.Uint32(h[len(h)-hashLen:])
		if got != want {
			return nil, nil, fmt.Errorf("crc mismatch: 0x%08x (given) != 0x%08x (bytes)", want, got)
		}
		h = h[:len(h)-hashLen]
	}
	// Extract subroute if any.

		for i, want := range keys {
			if want.CreatedBy != kms.StubCreatedBy {
				t.Fatalf("want key created by %s, got %s", kms.StubCreatedBy, want.CreatedBy)
			}
			if want.CreatedAt != kms.StubCreatedAt {
				t.Fatalf("want key created at %s, got %s", kms.StubCreatedAt, want.CreatedAt)
			}
			if test.wantKeyNames[i] != want.Name {
				t.Fatalf("want key name %s, got %s", test.wantKeyNames[i], want.Name)
			}
		}
	}

    /*
     * Don't bother testing. All non-primitive parameters are used only to construct error messages.
     * We never want to pass null for them, so we haven't annotated them to say that null is
     * allowed. But at the same time, it seems wasteful to bother inserting the checkNotNull calls
     * that NullPointerTester wants.
     *
     * (This empty method disables the automatic null testing provided by PackageSanityTests.)
     */
  }

## Adding Guava to your build

Guava's Maven group ID is `com.google.guava`, and its artifact ID is `guava`.
Guava provides two different "flavors": one for use on a (Java 8+) JRE and one
for use on Android or by any library that wants to be compatible with Android.
These flavors are specified in the Maven version field as either `33.5.0-jre` or
`33.5.0-android`. For more about depending on Guava, see
[using Guava in your build].

         * were running under a new enough version of Android to support NIO.
         *
         * So this is probably just the "Windows Java 8" case. In that case, if we wanted *another*
         * layer of fallback before consulting the system property, we could try
         * com.sun.security.auth.module.NTSystem.
         *