0xfffffffd,
		0xfffffffe,
		0xffffffff,
	}
	for _, x := range testCases {
		for _, y := range testCases {
			if got, want := sqDiff(x, y), orig(x, y); got != want {
				t.Fatalf("sqDiff(%#x, %#x): got %d, want %d", x, y, got, want)
			}
		}
	}
	if err := quick.CheckEqual(orig, sqDiff, &quick.Config{MaxCountScale: 10}); err != nil {
		t.Fatal(err)
	}

^bb0(%arg0: tensor<4xf32>):
  // CHECK:      [[CONST:%.*]] = "tfl.pseudo_const"() <{value = dense<1.000000e+00> : tensor<4xf32>}> : () -> tensor<4xf32>
  // CHECK-NEXT: [[SQDIFF:%.*]] = tfl.squared_difference %arg0, [[CONST]] : tensor<4xf32>
  // CHECK-NEXT: %{{.*}} = tfl.mul %arg0, [[SQDIFF]] {fused_activation_function = "NONE"} : tensor<4xf32>
  %0 = "tfl.pseudo_const" () {value = dense<1.0> : tensor<4xf32>} : () -> tensor<4xf32> loc("Const")

	ret, bestSum := 0, uint32(1<<32-1)
	for i, v := range p {
		vr, vg, vb, va := v.RGBA()
		sum := sqDiff(cr, vr) + sqDiff(cg, vg) + sqDiff(cb, vb) + sqDiff(ca, va)
		if sum < bestSum {
			if sum == 0 {
				return i
			}
			ret, bestSum = i, sum
		}
	}
	return ret
}

// sqDiff returns the squared-difference of x and y, shifted by 2 so that
// adding four of those won't overflow a uint32.
//

		-0x7ffffffe,
		-0x80000000,
	}
	for _, x := range testCases {
		for _, y := range testCases {
			if got, want := sqDiff(x, y), orig(x, y); got != want {
				t.Fatalf("sqDiff(%#x, %#x): got %d, want %d", x, y, got, want)
			}
		}
	}
	if err := quick.CheckEqual(orig, sqDiff, &quick.Config{MaxCountScale: 10}); err != nil {
		t.Fatal(err)
	}

				// TODO(nigeltao): consider smarter algorithms.
				bestIndex, bestSum := 0, uint32(1<<32-1)
				for index, p := range palette {
					sum := sqDiff(er, p[0]) + sqDiff(eg, p[1]) + sqDiff(eb, p[2]) + sqDiff(ea, p[3])
					if sum < bestSum {
						bestIndex, bestSum = index, sum
						if sum == 0 {
							break
						}
					}
				}
				pix[y*stride+x] = byte(bestIndex)

		ct:   "text/plain; charset=utf-8",
	},

	// Image types
	// For posterity, we originally returned "image/vnd.microsoft.icon" from
	// https://tools.ietf.org/html/draft-ietf-websec-mime-sniff-03#section-7
	// https://codereview.appspot.com/4746042
	// but that has since been replaced with "image/x-icon" in Section 6.2
	// of https://mimesniff.spec.whatwg.org/#matching-an-image-type-pattern

	if len(magic) != len(b) {
		return false
	}
	for i, c := range b {
		if magic[i] != c && magic[i] != '?' {
			return false
		}
	}
	return true
}

// sniff determines the format of r's data.
func sniff(r reader) format {
	formats, _ := atomicFormats.Load().([]format)
	for _, f := range formats {
		b, err := r.Peek(len(f.magic))
		if err == nil && match(f.magic, b) {
			return f
		}
	}

    the proxy will sniff the first few bytes of traffic to determine the protocol used. For certain "server first" protocols, such
    as the protocol used by `MySQL`, there will be no initial bytes to sniff. To mitigate this issue in the past, Istio introduced

func ExampleDecode() {
	// This example uses png.Decode which can only decode PNG images.
	// Consider using the general image.Decode as it can sniff and decode any registered image format.
	img, err := png.Decode(gopherPNG())
	if err != nil {
		log.Fatal(err)
	}

	levels := []string{" ", "░", "▒", "▓", "█"}

  // CHECK-DAG: %[[SQ_DIFF:.+]] = "tf.SquaredDifference"(%arg0, %[[MEAN_BCAST]]) : (tensor<3x4x256x6xf32>, tensor<3x4x256x6xf32>) -> tensor<3x4x256x6xf32>
  // CHECK-DAG: %[[VARIANCE:.+]] = "tf.Mean"(%[[SQ_DIFF]], %[[CST_AXIS]]) <{keep_dims = false}> : (tensor<3x4x256x6xf32>, tensor<3xi32>) -> tensor<256xf32>