if os.Getenv("IN_QEMU") == "1" {
		t.Skip("ignore the failure in QEMU; see golang.org/issue/9605")
	}
	t.FailNow()
	return nil
}

var diffCPUTimeImpl func(f func()) (user, system time.Duration)

func diffCPUTime(t *testing.T, f func()) (user, system time.Duration) {
	if fn := diffCPUTimeImpl; fn != nil {
		return fn(f)
	}
	t.Fatalf("cannot measure CPU time on GOOS=%s GOARCH=%s", runtime.GOOS, runtime.GOARCH)

	24: "cputime limit exceeded",
	25: "filesize limit exceeded",
	26: "virtual timer expired",
	27: "profiling timer expired",
	28: "window size changes",
	29: "information request",
	30: "user defined signal 1",
	31: "user defined signal 2",

	24: "cputime limit exceeded",
	25: "filesize limit exceeded",
	26: "virtual timer expired",
	27: "profiling timer expired",
	28: "window size changes",
	29: "information request",
	30: "user defined signal 1",
	31: "user defined signal 2",

	3:  "quit",
	4:  "illegal instruction",
	5:  "trace/breakpoint trap",
	6:  "aborted",
	7:  "bus error",
	8:  "floating point exception",
	9:  "killed",
	10: "user defined signal 1",
	11: "segmentation fault",
	12: "user defined signal 2",
	13: "broken pipe",
	14: "alarm clock",
	15: "terminated",
	16: "stack fault",
	17: "child exited",
	18: "continued",
	19: "stopped (signal)",

See <<toolchains#sec:configuring_toolchain_specifications,user manual>> for more information.

==== Using automatic toolchain downloading without having a repository configured

Automatic toolchain downloading without explicitly providing repositories to use is no longer supported.
See <<toolchains#sub:download_repositories,user manual>> for more information.

// CHECK-NEXT: _replication_info = "replicate"
// CHECK-SAME: device = "/device:TPU:0"
// CHECK-SAME: topology = "topology"
// CHECK:      return %[[CLUSTER]]#0, %[[CLUSTER]]#1, %[[CLUSTER]]#2


// Test a nested user of an op in a cluster has its operand be updated to
// `tf_device.cluster` result.
// CHECK-LABEL: func @nested_cluster_op_user
// CHECK-SAME: (%[[ARG_0:[a-z0-9]*]]: tensor<i1>)

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Static utility methods pertaining to the {@link Future} interface.
 *
 * <p>Many of these methods use the {@link ListenableFuture} API; consult the Guava User Guide
 * article on <a href="https://github.com/google/guava/wiki/ListenableFutureExplained">{@code
 * ListenableFuture}</a>.
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of

	3:  "quit",
	4:  "illegal instruction",
	5:  "trace/breakpoint trap",
	6:  "aborted",
	7:  "bus error",
	8:  "floating point exception",
	9:  "killed",
	10: "user defined signal 1",
	11: "segmentation fault",
	12: "user defined signal 2",
	13: "broken pipe",
	14: "alarm clock",
	15: "terminated",
	16: "stack fault",
	17: "child exited",
	18: "continued",
	19: "stopped (signal)",

	24: "cputime limit exceeded",
	25: "filesize limit exceeded",
	26: "virtual timer expired",
	27: "profiling timer expired",
	28: "window size changes",
	29: "information request",
	30: "user defined signal 1",
	31: "user defined signal 2",
	32: "thread AST",

	24: "cputime limit exceeded",
	25: "filesize limit exceeded",
	26: "virtual timer expired",
	27: "profiling timer expired",
	28: "window size changes",
	29: "information request",
	30: "user defined signal 1",
	31: "user defined signal 2",
	32: "power fail/restart",