You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: graph_test.go
    path of file: ./repos/terraform/internal/addrs
    
    the code of the file until where you have to start completion: // Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1

package addrs

import (
	"strings"
	"testing"
)

func TestGraph(t *testing.T) {
	a := LocalValue{Name: "a"}
	b := LocalValue{Name: "b"}
	c := LocalValue{Name: "c"}
	d := LocalValue{Name: "d"}

	g := NewDirectedGraph[LocalValue]()

	g.AddDependency(d, c)
	g.AddDependency(d, b)
	g.AddDependency(c, b)
	g.AddDependency(b, a)

	t.Run("StringForComparison", func(t *testing.T) {
		gotStr := strings.TrimSpace(g.StringForComparison())
		wantStr := strings.TrimSpace(`
local.a
local.b
  local.a
local.c
  local.b
local.d
  local.b
  local.c
`)
		if gotStr != wantStr {
			t.Errorf("wrong string representation\ngot:\n%s\n\nwant:\n%s", gotStr, wantStr)
		}
	})

	t.Run("direct dependencies of a", func(t *testing.T) {
		deps := g.DirectDependenciesOf(a)
		if got, want := len(deps), 0; got != want {
			t.Errorf("a has %d dependencies, but should have %d", got, want)
		}
	})
	t.Run("direct dependencies of b", func(t *testing.T) {
		deps := g.DirectDependenciesOf(b)
		if got, want := len(deps), 1; got != want {
			t.Errorf("b has %d dependencies, but should have %d", got, want)
		}
		if !deps.Has(a) {
			t.Errorf("b does not depend on a, but should")
		}
	})
	t.Run("direct dependencies of d", func(t *testing.T) {
		deps := g.DirectDependenciesOf(d)
		if got, want := len(deps), 2; got != want {
			t.Errorf("d has %d dependencies, but should have %d", got, want)
		}
		if !deps.Has(b) {
			t.Errorf("d does not depend on b, but should")
		}
		if !deps.Has(c) {
			t.Errorf("d does not depend on c, but should")
		}
	})
	t.Run("direct dependents of a", func(t *testing.T) {
		depnts := g.DirectDependentsOf(a)
		if got, want := len(depnts), 1; got != want {
			t.Errorf("a has %d dependents, but should have %d", got, want)
		}
		if !depnts.Has(b) {
			t.Errorf("b does not depend on a, but should")
		}
	})
	t.Run("direct dependents of b", func(t *testing.T) {
		depnts := g.DirectDependentsOf(b)
		if got, want := len(depnts), 2; got != want {
			t.Errorf("b has %d dependents, but should have %d", got, want)
		}
		if !depnts.Has(c) {
			t.Errorf("c does not depend on b, but should")
		}
		if !depnts.Has(d) {
			t.Errorf("d does not depend on b, but should")
		}
	})
	t.Run("direct dependents of d", func(t *testing.T) {
		depnts := g.DirectDependents
    
func TestGraph(t *testing.T) {
	a := LocalValue{Name: "a"}
	b := LocalValue{Name: "b"}
	c := LocalValue{Name: "c"}
	d := LocalValue{Name: "d"}

	g := NewDirectedGraph[LocalValue]()

	g.AddDependency(d, c)
	g.AddDependency(d, b)
	g.AddDependency(c, b)
	g.AddDependency(b, a)

	t.Run("StringForComparison", func(t *testing.T) {
		gotStr := strings.TrimSpace(g.StringForComparison())
		wantStr := strings.TrimSpace(`
local.a
local.b
  local.a
local.c
  local.b
local.d
  local.b
  local.c
`)
		if gotStr != wantStr {
			t.Errorf("wrong string representation\ngot:\n%s\n\nwant:\n%s", gotStr, wantStr)
		}
	})

	t.Run("direct dependencies of a", func(t *testing.T) {
		deps := g.DirectDependenciesOf(a)
		if got, want := len(deps), 0; got != want {
			t.Errorf("a has %d dependencies, but should have %d", got, want)
		}
	})
	t.Run("direct dependencies of b", func(t *testing.T) {
		deps := g.DirectDependenciesOf(b)
		if got, want := len(deps), 1; got != want {
			t.Errorf("b has %d dependencies, but should have %d", got, want)
		}
		if !deps.Has(a) {
			t.Errorf("b does not depend on a, but should")
		}
	})
	t.Run("direct dependencies of d", func(t *testing.T) {
		deps := g.DirectDependenciesOf(d)
		if got, want := len(deps), 2; got != want {
			t.Errorf("d has %d dependencies, but should have %d", got, want)
		}
		if !deps.Has(b) {
			t.Errorf("d does not depend on b, but should")
		}
		if !deps.Has(c) {
			t.Errorf("d does not depend on c, but should")
		}
	})
	t.Run("direct dependents of a", func(t *testing.T) {
		depnts := g.DirectDependentsOf(a)
		if got, want := len(depnts), 1; got != want {
			t.Errorf("a has %d dependents, but should have %d", got, want)
		}
		if !depnts.Has(b) {
			t.Errorf("b does not depend on a, but should")
		}
	})
	t.Run("direct dependents of b", func(t *testing.T) {
		depnts := g.DirectDependentsOf(b)
		if got, want := len(depnts), 2; got != want {
			t.Errorf("b has %d dependents, but should have %d", got, want)
		}
		if !depnts.Has(c) {
			t.Errorf("c does not depend on b, but should")
		}
		if !depnts.Has(d) {
			t.Errorf("d does not depend on b, but should")
		}
	})
	t.Run("direct dependents of d", func(t *testing.T) {
		depnts := g.DirectDependentsOf(d)
		if got, want := len(depnts), 0; got != want {
			t.Errorf("d has %d dependents, but should have %d", got, want)
		}
	})
	t.Run("transitive dependencies of a", func(t *testing.T) {
		deps := g.TransitiveDependenciesOf(a)
		if got, want := len(deps), 0; got != want {
			t.Errorf("a has %d transitive dependencies, but should have %d", got, want)
		}
	})
	t.Run("transitive dependencies of b", func(t *testing.T) {
		deps := g.TransitiveDependenciesOf(b)
		if got, want := len(deps), 1; got != want {
			t.Errorf("b has %d transitive dependencies, but should have %d", got, want)
		}
		if !deps.Has(a) {
			t.Errorf("b does not depend on a, but should")
		}
	})
	t.Run("transitive dependencies of d", func(t *testing.T) {
		deps := g.TransitiveDependenciesOf(d)
		if got, want := len(deps), 3; got != want {
			t.Errorf("d has %d transitive dependencies, but should have %d", got, want)
		}
		if !deps.Has(a) {
			t.Errorf("d does not depend on a, but should")
		}
		if !deps.Has(b) {
			t.Errorf("d does not depend on b, but should")
		}
		if !deps.Has(c) {
			t.Errorf("d does not depend on c, but should")
		}
	})
	t.Run("transitive dependents of a", func(t *testing.T) {
		depnts := g.TransitiveDependentsOf(a)
		if got, want := len(depnts), 3; got != want {
			t.Errorf("a has %d transitive dependents, but should have %d", got, want)
		}
		if !depnts.Has(b) {
			t.Errorf("b does not depend on a, but should")
		}
		if !depnts.Has(c) {
			t.Errorf("c does not depend on a, but should")
		}
		if !depnts.Has(d) {
			t.Errorf("d does not depend on a, but should")
		}
	})
	t.Run("transitive dependents of b", func(t *testing.T) {
		depnts := g.TransitiveDependentsOf(b)
		if got, want := len(depnts), 2; got != want {
			t.Errorf("b has %d transitive dependents, but should have %d", got, want)
		}
		if !depnts.Has(c) {
			t.Errorf("c does not depend on b, but should")
		}
		if !depnts.Has(d) {
			t.Errorf("d does not depend on b, but should")
		}
	})
	t.Run("transitive dependents of d", func(t *testing.T) {
		depnts := g.TransitiveDependentsOf(d)
		if got, want := len(depnts), 0; got != want {
			t.Errorf("d has %d transitive dependents, but should have %d", got, want)
		}
	})
}