MAP_VARIABLE                  = 0x0
	MCAST_BLOCK_SOURCE            = 0x40
	MCAST_EXCLUDE                 = 0x2
	MCAST_INCLUDE                 = 0x1
	MCAST_JOIN_GROUP              = 0x3e
	MCAST_JOIN_SOURCE_GROUP       = 0x42
	MCAST_LEAVE_GROUP             = 0x3f
	MCAST_LEAVE_SOURCE_GROUP      = 0x43
	MCAST_SOURCE_FILTER           = 0x49
	MCAST_UNBLOCK_SOURCE          = 0x41
	MCL_CURRENT                   = 0x100

  for (const bool expected : {false, true}) {
    const Scope& scope = expected ? scope_expected_ : scope_test_;
    // Construct forward graph.
    auto a = Const(scope, 1, {4, 2});
    auto b = Const(scope, 2, {4, 2});
    auto c = Const(scope, 3, {4, 2});

    auto pack = Stack(scope, {a, b, c});
    auto unpack = Unstack(scope, pack.output, 3);
    TF_ASSERT_OK(scope.status());

    // Construct grad inputs.

float64 %b 36167929443327e-159 8135819834632444p-536
float64 %b 609610927149051e-255 4576664294594737p-850
float64 %b 3743626360493413e-165 6898586531774201p-549
float64 %b 94080055902682397e-242 6273271706052298p-800
float64 %b 899810892172646163e+283 7563892574477827p+947
float64 %b 7120190517612959703e+120 5385467232557565p+409
float64 %b 25188282901709339043e-252 5635662608542340p-825

	0xc7, 0x64, 0x42, 0x25, 0xc6, 0x64, 0x26, 0x41, 0x66, 0x26, 0x08, 0x93, 0x4c, 0x5e, 0xb6, 0xe3,
	0x5c, 0xe5, 0x51, 0xa4, 0x05, 0x5a, 0x9a, 0xba, 0x96, 0x18, 0x8b, 0x8f, 0xf2, 0x92, 0x72, 0x5d,
	0xa0, 0x40, 0x7f, 0x42, 0x56, 0x5d, 0x76, 0xd1, 0xfe, 0x83, 0xae, 0x8a, 0x76, 0xd3, 0x65, 0x76,
	0xcd, 0x32, 0xed, 0x42, 0x68, 0xd4, 0xbf, 0xd0, 0x45, 0x9b, 0x55, 0x71, 0x2f, 0x2f, 0x49, 0x51,

	0x18, 0x7d, 0x57, 0x03, 0x68, 0x1a, 0xb6, 0x65, 0x1a, 0xbc, 0x65, 0xc8, 0x73, 0xf3, 0xfb, 0x1b,
	0xd6, 0xd7, 0x63, 0xf5, 0x62, 0xd3, 0x92, 0xdf, 0x58, 0x81, 0x46, 0xef, 0x69, 0x30, 0x41, 0xc3,
	0x1d, 0x5f, 0xae, 0xa2, 0xbc, 0xb9, 0x18, 0xbf, 0xf8, 0xd5, 0xbe, 0xda, 0x52, 0x55, 0x00, 0x2a,
	0x53, 0xed, 0x56, 0x71, 0x42, 0xa5, 0xe0, 0x94, 0x01, 0xe8, 0x07, 0x1a, 0x14, 0x9a, 0x51, 0xcd,

	IFT_FRELAYDCE                     = 0x2c
	IFT_FRF16MFRBUNDLE                = 0xa3
	IFT_FRFORWARD                     = 0x9e
	IFT_G703AT2MB                     = 0x43
	IFT_G703AT64K                     = 0x42
	IFT_GIF                           = 0xf0
	IFT_GIGABITETHERNET               = 0x75
	IFT_GR303IDT                      = 0xb2
	IFT_GR303RDT                      = 0xb1
	IFT_H323GATEKEEPER                = 0xa4

	IFT_FRELAYDCE                     = 0x2c
	IFT_FRF16MFRBUNDLE                = 0xa3
	IFT_FRFORWARD                     = 0x9e
	IFT_G703AT2MB                     = 0x43
	IFT_G703AT64K                     = 0x42
	IFT_GIF                           = 0xf0
	IFT_GIGABITETHERNET               = 0x75
	IFT_GR303IDT                      = 0xb2
	IFT_GR303RDT                      = 0xb1
	IFT_H323GATEKEEPER                = 0xa4

	0x88, 0xa2, 0x00, 0x8d, 0x3d, 0x34, 0x85, 0x22, 0x55, 0xd8, 0x98, 0xa0, 0xdf, 0xd3, 0xb3, 0x12,
	0x7d, 0x5d, 0xa1, 0x37, 0x5e, 0xa0, 0xdf, 0xa3, 0xd2, 0x43, 0x9e, 0xc0, 0x46, 0xc0, 0xd0, 0xd7,
	0xaf, 0x55, 0xb5, 0xbd, 0x42, 0xe3, 0x7d, 0x23, 0x69, 0x1d, 0x63, 0xfe, 0x3d, 0x1b, 0x93, 0x3b,
	0x46, 0x97, 0xa1, 0xdf, 0x76, 0x5e, 0xb9, 0x89, 0x92, 0xb0, 0x50, 0xa9, 0x40, 0x86, 0x50, 0xb2,

	0xfb, 0x4d, 0x1c, 0x6b, 0x83, 0x04, 0x62, 0x40,
	0x00, 0x11, 0x42, 0x00, 0x00, 0x00, 0x54, 0x83,
	0xb8, 0x4f, 0x10, 0x8e, 0x89, 0x46, 0xde, 0xf7,
	0x13, 0x31, 0x00, 0x20, 0x00, 0x00, 0x00, 0x90,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x0a, 0x10, 0x00,
	0x01, 0x00, 0x00, 0xf0, 0x5b, 0xf4, 0xbe, 0x3d,
	0xbe, 0xcf, 0xf7, 0xaf, 0x42, 0x04, 0x84, 0x41,
	// Entry 500 - 53F
	0x30, 0xff, 0x79, 0x72, 0x04, 0x00, 0x00, 0x49,

	0xe7, 0x63, 0xa7, 0xeb, 0x05, 0x84, 0x8d, 0x6a, 0x61, 0xcf, 0x95, 0x06, 0x5e, 0x13, 0x84, 0x0b,
	0x1c, 0x7a, 0x2e, 0xa3, 0x83, 0xb0, 0x36, 0x3c, 0xae, 0xb9, 0x24, 0x20, 0x0c, 0x0b, 0xd2, 0xb1,
	0x42, 0x46, 0x05, 0x85, 0x47, 0x11, 0xdb, 0x4a, 0xb3, 0xad, 0xb0, 0xe7, 0x4a, 0x03, 0xb7, 0xd2,
	0x6c, 0x6b, 0x78, 0xbc, 0xfb, 0xb1, 0xeb, 0x89, 0xee, 0xa0, 0x6d, 0x39, 0xd4, 0xaf, 0xb9, 0xd4,