}

	oe, ok := err.(*OpError)
	if !ok || oe.Op != "dial" {
		t.Fatalf("Dial error = %#v; want dial *OpError", err)
	}

	if oe.Err != errCanceled {
		t.Errorf("DialContext = (%v, %v); want OpError with error %v", c, err, errCanceled)
	}

	case *fs.PathError: // for Plan 9
		return nil
	}
	return fmt.Errorf("unexpected type on 1st nested level: %T", nestedErr)
}

func TestContextError(t *testing.T) {
	if !errors.Is(errCanceled, context.Canceled) {
		t.Error("errCanceled is not context.Canceled")
	}
	if !errors.Is(errTimeout, context.DeadlineExceeded) {
		t.Error("errTimeout is not context.DeadlineExceeded")
	}

	errNoSuitableAddress = errors.New("no suitable address found")

	// For connection setup and write operations.
	errMissingAddress = errors.New("missing address")

	// For both read and write operations.
	errCanceled         = canceledError{}
	ErrWriteToConnected = errors.New("use of WriteTo with pre-connected connection")
)

// canceledError lets us return the same error string we have always

					}
				}

				t.Fatalf("dial error after %d ticks (%d before cancel sent): %v",
					ticks, cancelTick-ticks, err)
			}
			if oe, ok := err.(*OpError); !ok || oe.Err != errCanceled {
				t.Fatalf("dial error = %v (%T); want OpError with Err == errCanceled", err, err)
			}
			return // success.
		}
	}
}

func TestCancelAfterDial(t *testing.T) {
	if testing.Short() {
		t.Skip("avoiding time.Sleep")
	}

		}
		t.Logf("testHookLookupIP performing lookup")
		return fn(ctx, network, host)
	}

	_, err := DefaultResolver.LookupIPAddr(lookupCtx, "google.com")
	if dnsErr, ok := err.(*DNSError); !ok || dnsErr.Err != errCanceled.Error() {
		t.Errorf("unexpected error from canceled, blocked LookupIPAddr: %v", err)
	}
	close(unblockLookup)
}

// Issue 24330: treat the nil *Resolver like a zero value. Verify nothing