return %cluster : tensor<i32>
    }
    ```

    will be transformed into:

    ```mlir
    func @computation(%arg0: tensor<i32>) -> tensor<i32> {
      %cluster = "tf_device.cluster_func"(%arg0) {func = @_func} : (tensor<i32>) -> tensor<i32>
      return %cluster : tensor<i32>
    }

    func @_func(%arg0: tensor<i32>) -> tensor<i32> {
      %identity = "tf.Identity"(%arg0) : (tensor<i32>) -> tensor<i32>

        'a( a b c )'                                       | 'a'     | [tokens('a b c')]
        'a( a b, c d + f )'                                | 'a'     | [tokens('a b'), tokens('c d + f')]
        '_func(1+2)'                                       | '_func' | [tokens('1+2')]
        'a(A, B(1+2))'                                     | 'a'     | [token('A'), expression('B(1+2)')]

`cluster_func`.

For example, given the following `cluster_func` wrapping `func`:

```mlir
  func @test(%arg0: tensor<*xi32>) {
    "tf_device.cluster_func"(%arg0) {
        func = @func,
        step_marker_location = ""} : (tensor<*xi32>) -> tensor<*xi32>
    return
  }

  func @func(%arg0: tensor<*xi32>) -> tensor<*xi32> {
    %0 = "tf.XlaSharding"(%arg0) {_XlaSharding = "\01\02\03",

		p = pp.Append(p, wasm.AI64Store, 0, 0, 0, obj.TYPE_CONST, 0, off+i)
	}

	return p
}

func ginsnop(pp *objw.Progs) *obj.Prog {
	return pp.Prog(wasm.ANop)
}

func ssaMarkMoves(s *ssagen.State, b *ssa.Block) {
}

func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
	switch b.Kind {
	case ssa.BlockPlain:
		if next != b.Succs[0].Block() {

			Funcs: template.FuncMap{
				"Less": func(name, i, j string) string {
					return fmt.Sprintf("%s.Less(%s, %s)", name, i, j)
				},
				"Swap": func(name, i, j string) string {
					return fmt.Sprintf("%s.Swap(%s, %s)", name, i, j)
				},
			},
		},
		Variant{
			Name:       "func",
			Path:       "zsortfunc.go",
			Package:    "sort",
			Imports:    "",
			FuncSuffix: "_func",
			TypeParam:  "",
			ExtraParam: "",

	{_Const, "const", 0, 0},
	{_Continue, "continue", 0, 0},
	{_Default, "default", 0, 0},
	{_Defer, "defer", 0, 0},
	{_Else, "else", 0, 0},
	{_Fallthrough, "fallthrough", 0, 0},
	{_For, "for", 0, 0},
	{_Func, "func", 0, 0},
	{_Go, "go", 0, 0},
	{_Goto, "goto", 0, 0},
	{_If, "if", 0, 0},
	{_Import, "import", 0, 0},
	{_Interface, "interface", 0, 0},
	{_Map, "map", 0, 0},
	{_Package, "package", 0, 0},

func TestB(t *testing.T) {
	if BFunc() == 1010101 {
		t.Fatalf("bad!")
	}
}
-- c/c.go --
package c

var G int

func CFunc(x, y int) int {
	G += x
	G -= y
	return x + y
}
-- c/c_test.go --
package c

import "testing"

func TestC(t *testing.T) {
	if CFunc(10, 10) == 1010101 {
		t.Fatalf("bad!")
	}
}
-- d/d.go --
package d

const FortyTwo = 42

//	   filename[0]
//	   filename[1]
//
// Looking up a filename then becomes:
//  0. Given a func, and filename index [K]
//  1. Get Func.CUIndex:       M := func.cuOffset
//  2. Find filename offset:   fileOffset := runtime.cutab[M+K]
//  3. Get the filename:       getcstring(runtime.filetab[fileOffset])
func (state *pclntab) generateFilenameTabs(ctxt *Link, compUnits []*sym.CompilationUnit, funcs []loader.Sym) []uint32 {

import (
	"M/a"
	"M/b"
)

func MFunc() string {
	return "42"
}

func M2Func() int {
	return a.AFunc() + b.BFunc()
}

func init() {
	println("package 'main' init")
}

func main() {
	println(a.AFunc() + b.BFunc())
}
-- main/main_test.go --
package main

import "testing"

func TestMain(t *testing.T) {
	if MFunc() != "42" {
		t.Fatalf("bad!")
	}

}

func init() {
	println("package 'main' init")
}

func main() {
	println(a.AFunc() + b.BFunc())
}
-- main/main_test.go --
package main

import "testing"

func TestMain(t *testing.T) {
	if MFunc() != "42" {
		t.Fatalf("bad!")
	}
	if M2Func() != 0 {
		t.Fatalf("also bad!")
	}
}
-- n/n.go --
package n

type N int
-- onlytest/mumble_test.go --