diff --git a/.gitignore b/.gitignore
index b20db27..8cffe7a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@
 .testCoverage.txt
 .testCoverage.txt.tmp
 coverage.html
+coverage.out
 /exported
 /release
 /schemactl
diff --git a/domain/commands_test.go b/domain/commands_test.go
index aec95ac..4fa063e 100644
--- a/domain/commands_test.go
+++ b/domain/commands_test.go
@@ -7,10 +7,68 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"gitlab.com/unboundsoftware/eventsourced/eventsourced"
 
 	"gitlab.com/unboundsoftware/schemas/hash"
 )
 
+// AddOrganization tests
+
+func TestAddOrganization_Validate_Success(t *testing.T) {
+	cmd := AddOrganization{
+		Name:      "Test Org",
+		Initiator: "user@example.com",
+	}
+
+	org := &Organization{} // New organization with no identity
+	err := cmd.Validate(context.Background(), org)
+	assert.NoError(t, err)
+}
+
+func TestAddOrganization_Validate_AlreadyExists(t *testing.T) {
+	cmd := AddOrganization{
+		Name:      "Test Org",
+		Initiator: "user@example.com",
+	}
+
+	org := &Organization{
+		BaseAggregate: eventsourced.BaseAggregateFromString("existing-org-id"),
+	}
+
+	err := cmd.Validate(context.Background(), org)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "already exists")
+}
+
+func TestAddOrganization_Validate_EmptyName(t *testing.T) {
+	cmd := AddOrganization{
+		Name:      "",
+		Initiator: "user@example.com",
+	}
+
+	org := &Organization{}
+	err := cmd.Validate(context.Background(), org)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "name is required")
+}
+
+func TestAddOrganization_Event(t *testing.T) {
+	cmd := AddOrganization{
+		Name:      "Test Org",
+		Initiator: "user@example.com",
+	}
+
+	event := cmd.Event(context.Background())
+	require.NotNil(t, event)
+
+	orgEvent, ok := event.(*OrganizationAdded)
+	require.True(t, ok)
+	assert.Equal(t, "Test Org", orgEvent.Name)
+	assert.Equal(t, "user@example.com", orgEvent.Initiator)
+}
+
+// AddAPIKey tests
+
 func TestAddAPIKey_Event(t *testing.T) {
 	type fields struct {
 		Name      string
@@ -74,3 +132,335 @@ func TestAddAPIKey_Event(t *testing.T) {
 		})
 	}
 }
+
+func TestAddAPIKey_Validate_Success(t *testing.T) {
+	cmd := AddAPIKey{
+		Name:      "production-key",
+		Key:       "us_ak_1234567890123456",
+		Refs:      []string{"main"},
+		Read:      true,
+		Publish:   false,
+		Initiator: "user@example.com",
+	}
+
+	org := &Organization{
+		BaseAggregate: eventsourced.BaseAggregateFromString("org-123"),
+		APIKeys:       []APIKey{},
+	}
+
+	err := cmd.Validate(context.Background(), org)
+	assert.NoError(t, err)
+}
+
+func TestAddAPIKey_Validate_OrganizationNotExists(t *testing.T) {
+	cmd := AddAPIKey{
+		Name:      "production-key",
+		Key:       "us_ak_1234567890123456",
+		Refs:      []string{"main"},
+		Read:      true,
+		Publish:   false,
+		Initiator: "user@example.com",
+	}
+
+	org := &Organization{} // No identity means it doesn't exist
+	err := cmd.Validate(context.Background(), org)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "does not exist")
+}
+
+func TestAddAPIKey_Validate_DuplicateKeyName(t *testing.T) {
+	cmd := AddAPIKey{
+		Name:      "existing-key",
+		Key:       "us_ak_1234567890123456",
+		Refs:      []string{"main"},
+		Read:      true,
+		Publish:   false,
+		Initiator: "user@example.com",
+	}
+
+	org := &Organization{
+		BaseAggregate: eventsourced.BaseAggregateFromString("org-123"),
+		APIKeys: []APIKey{
+			{
+				Name: "existing-key",
+				Key:  "hashed-key",
+			},
+		},
+	}
+
+	err := cmd.Validate(context.Background(), org)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "already exist")
+	assert.Contains(t, err.Error(), "existing-key")
+}
+
+// UpdateSubGraph tests
+
+func TestUpdateSubGraph_Validate_Success(t *testing.T) {
+	url := "http://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "users",
+		Url:            &url,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	assert.NoError(t, err)
+}
+
+func TestUpdateSubGraph_Validate_MissingRef(t *testing.T) {
+	url := "http://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "",
+		Service:        "users",
+		Url:            &url,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "ref is missing")
+}
+
+func TestUpdateSubGraph_Validate_RefWhitespaceOnly(t *testing.T) {
+	url := "http://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "   ",
+		Service:        "users",
+		Url:            &url,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "ref is missing")
+}
+
+func TestUpdateSubGraph_Validate_MissingService(t *testing.T) {
+	url := "http://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "",
+		Url:            &url,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "service is missing")
+}
+
+func TestUpdateSubGraph_Validate_ServiceWhitespaceOnly(t *testing.T) {
+	url := "http://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "   ",
+		Url:            &url,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "service is missing")
+}
+
+func TestUpdateSubGraph_Validate_MissingSDL(t *testing.T) {
+	url := "http://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "users",
+		Url:            &url,
+		Sdl:            "",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "SDL is missing")
+}
+
+func TestUpdateSubGraph_Validate_SDLWhitespaceOnly(t *testing.T) {
+	url := "http://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "users",
+		Url:            &url,
+		Sdl:            "   \n\t  ",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "SDL is missing")
+}
+
+func TestUpdateSubGraph_Validate_MissingURL_NoExistingURL(t *testing.T) {
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "users",
+		Url:            nil,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+		Url:           nil, // No existing URL
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "url is missing")
+}
+
+func TestUpdateSubGraph_Validate_MissingURL_HasExistingURL(t *testing.T) {
+	existingURL := "http://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "users",
+		Url:            nil,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+		Url:           &existingURL, // Has existing URL, so nil is OK
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	assert.NoError(t, err)
+}
+
+func TestUpdateSubGraph_Validate_EmptyURL_NoExistingURL(t *testing.T) {
+	emptyURL := ""
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "users",
+		Url:            &emptyURL,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+		Url:           nil,
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "url is missing")
+}
+
+func TestUpdateSubGraph_Validate_URLWhitespaceOnly_NoExistingURL(t *testing.T) {
+	whitespaceURL := "   "
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "users",
+		Url:            &whitespaceURL,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	subGraph := &SubGraph{
+		BaseAggregate: eventsourced.BaseAggregateFromString("subgraph-123"),
+		Url:           nil,
+	}
+
+	err := cmd.Validate(context.Background(), subGraph)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "url is missing")
+}
+
+func TestUpdateSubGraph_Validate_WrongAggregateType(t *testing.T) {
+	url := "http://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "users",
+		Url:            &url,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	// Pass wrong aggregate type
+	org := &Organization{
+		BaseAggregate: eventsourced.BaseAggregateFromString("org-123"),
+	}
+
+	err := cmd.Validate(context.Background(), org)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "not a SubGraph")
+}
+
+func TestUpdateSubGraph_Event(t *testing.T) {
+	url := "http://example.com/graphql"
+	wsURL := "ws://example.com/graphql"
+	cmd := UpdateSubGraph{
+		OrganizationId: "org-123",
+		Ref:            "main",
+		Service:        "users",
+		Url:            &url,
+		WSUrl:          &wsURL,
+		Sdl:            "type Query { hello: String }",
+		Initiator:      "user@example.com",
+	}
+
+	event := cmd.Event(context.Background())
+	require.NotNil(t, event)
+
+	subGraphEvent, ok := event.(*SubGraphUpdated)
+	require.True(t, ok)
+	assert.Equal(t, "org-123", subGraphEvent.OrganizationId)
+	assert.Equal(t, "main", subGraphEvent.Ref)
+	assert.Equal(t, "users", subGraphEvent.Service)
+	assert.Equal(t, url, *subGraphEvent.Url)
+	assert.Equal(t, wsURL, *subGraphEvent.WSUrl)
+	assert.Equal(t, "type Query { hello: String }", subGraphEvent.Sdl)
+	assert.Equal(t, "user@example.com", subGraphEvent.Initiator)
+}
diff --git a/sdlmerge/sdlmerge_test.go b/sdlmerge/sdlmerge_test.go
new file mode 100644
index 0000000..1d74584
--- /dev/null
+++ b/sdlmerge/sdlmerge_test.go
@@ -0,0 +1,434 @@
+package sdlmerge
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMergeSDLs_Success(t *testing.T) {
+	// Both types need to be in the same subgraph or properly federated
+	sdl1 := `
+		type User {
+			id: ID!
+			name: String!
+		}
+
+		type Post {
+			id: ID!
+			title: String!
+		}
+	`
+
+	result, err := MergeSDLs(sdl1)
+	require.NoError(t, err)
+	assert.Contains(t, result, "User")
+	assert.Contains(t, result, "Post")
+	assert.Contains(t, result, "id")
+	assert.Contains(t, result, "name")
+	assert.Contains(t, result, "title")
+}
+
+func TestMergeSDLs_SingleSchema(t *testing.T) {
+	sdl := `
+		type Query {
+			hello: String
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "Query")
+	assert.Contains(t, result, "hello")
+}
+
+func TestMergeSDLs_EmptySchemas(t *testing.T) {
+	result, err := MergeSDLs()
+	require.NoError(t, err)
+	// With no schemas, result will be empty after processing
+	// This is valid - just verifies no crash
+	_ = result
+}
+
+func TestMergeSDLs_InvalidSyntax(t *testing.T) {
+	invalidSDL := `
+		type User {
+			id: ID!
+			name: String!
+			// Missing closing brace
+	`
+
+	_, err := MergeSDLs(invalidSDL)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "parse graphql document string")
+}
+
+func TestMergeSDLs_UnknownType(t *testing.T) {
+	sdl := `
+		type User {
+			id: ID!
+			profile: UnknownType
+		}
+	`
+
+	_, err := MergeSDLs(sdl)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "validate schema")
+}
+
+func TestMergeSDLs_DuplicateTypes_DifferentFields(t *testing.T) {
+	// Same type with different fields in different subgraphs - should fail
+	// In federation, shared types must be identical
+	sdl1 := `
+		type User {
+			id: ID!
+		}
+	`
+	sdl2 := `
+		type User {
+			name: String!
+		}
+	`
+
+	_, err := MergeSDLs(sdl1, sdl2)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "shared type")
+}
+
+func TestMergeSDLs_ExtendType(t *testing.T) {
+	sdl1 := `
+		type User {
+			id: ID!
+		}
+	`
+	sdl2 := `
+		extend type User {
+			email: String!
+		}
+	`
+
+	result, err := MergeSDLs(sdl1, sdl2)
+	require.NoError(t, err)
+	assert.Contains(t, result, "User")
+	assert.Contains(t, result, "id")
+	assert.Contains(t, result, "email")
+}
+
+func TestMergeSDLs_Scalars(t *testing.T) {
+	sdl := `
+		scalar DateTime
+
+		type Event {
+			id: ID!
+			createdAt: DateTime!
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "DateTime")
+	assert.Contains(t, result, "Event")
+}
+
+func TestMergeSDLs_Enums(t *testing.T) {
+	sdl := `
+		enum Role {
+			ADMIN
+			USER
+			GUEST
+		}
+
+		type User {
+			id: ID!
+			role: Role!
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "Role")
+	assert.Contains(t, result, "ADMIN")
+	assert.Contains(t, result, "USER")
+}
+
+func TestMergeSDLs_Interfaces(t *testing.T) {
+	sdl := `
+		interface Node {
+			id: ID!
+		}
+
+		type User implements Node {
+			id: ID!
+			name: String!
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "Node")
+	assert.Contains(t, result, "implements")
+}
+
+func TestMergeSDLs_Unions(t *testing.T) {
+	sdl := `
+		type User {
+			id: ID!
+			name: String!
+		}
+
+		type Bot {
+			id: ID!
+			version: String!
+		}
+
+		union Actor = User | Bot
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "Actor")
+	assert.Contains(t, result, "User")
+	assert.Contains(t, result, "Bot")
+}
+
+func TestMergeSDLs_InputTypes(t *testing.T) {
+	sdl := `
+		input CreateUserInput {
+			name: String!
+			email: String!
+		}
+
+		type Mutation {
+			createUser(input: CreateUserInput!): User
+		}
+
+		type User {
+			id: ID!
+			name: String!
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "CreateUserInput")
+	assert.Contains(t, result, "createUser")
+}
+
+func TestMergeSDLs_Directives(t *testing.T) {
+	sdl := `
+		type User {
+			id: ID!
+			name: String! @deprecated(reason: "Use fullName instead")
+			fullName: String!
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "User")
+	assert.Contains(t, result, "name")
+	assert.Contains(t, result, "fullName")
+}
+
+func TestMergeSDLs_FederationKeys(t *testing.T) {
+	// Federation @key directive
+	sdl := `
+		type User @key(fields: "id") {
+			id: ID!
+			name: String!
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "User")
+	// @key directive should be removed during merge
+	assert.NotContains(t, result, "@key")
+}
+
+func TestMergeSDLs_ExternalFields(t *testing.T) {
+	// Federation @external directive
+	sdl1 := `
+		type User @key(fields: "id") {
+			id: ID!
+			name: String!
+		}
+	`
+	sdl2 := `
+		extend type User @key(fields: "id") {
+			id: ID! @external
+			posts: [Post!]!
+		}
+
+		type Post {
+			id: ID!
+			title: String!
+		}
+	`
+
+	result, err := MergeSDLs(sdl1, sdl2)
+	require.NoError(t, err)
+	assert.Contains(t, result, "User")
+	assert.Contains(t, result, "Post")
+	// @external fields should be removed
+	assert.NotContains(t, result, "@external")
+}
+
+func TestMergeSDLs_ComplexSchema(t *testing.T) {
+	// Multiple subgraphs with various types - simplified to avoid cross-references
+	users := `
+		type User @key(fields: "id") {
+			id: ID!
+			username: String!
+			email: String!
+		}
+
+		type Query {
+			user(id: ID!): User
+			users: [User!]!
+		}
+	`
+
+	posts := `
+		extend type User @key(fields: "id") {
+			id: ID! @external
+			posts: [Post!]!
+		}
+
+		type Post @key(fields: "id") {
+			id: ID!
+			title: String!
+			content: String!
+		}
+
+		extend type Query {
+			post(id: ID!): Post
+			posts: [Post!]!
+		}
+	`
+
+	comments := `
+		extend type Post @key(fields: "id") {
+			id: ID! @external
+			comments: [Comment!]!
+		}
+
+		type Comment {
+			id: ID!
+			text: String!
+		}
+
+		extend type Query {
+			comment(id: ID!): Comment
+		}
+	`
+
+	result, err := MergeSDLs(users, posts, comments)
+	require.NoError(t, err)
+
+	// Verify all types are present
+	assert.Contains(t, result, "User")
+	assert.Contains(t, result, "Post")
+	assert.Contains(t, result, "Comment")
+	assert.Contains(t, result, "Query")
+
+	// Verify fields from all subgraphs
+	assert.Contains(t, result, "username")
+	assert.Contains(t, result, "posts")
+	assert.Contains(t, result, "comments")
+}
+
+func TestMergeSDLs_EmptyTypeDefinition(t *testing.T) {
+	sdl := `
+		type Empty {}
+	`
+
+	_, err := MergeSDLs(sdl)
+	require.Error(t, err)
+	// Empty types are invalid in GraphQL
+	assert.Contains(t, err.Error(), "empty body")
+}
+
+func TestMergeSDLs_MultipleValidationErrors(t *testing.T) {
+	// Schema with multiple errors
+	sdl := `
+		type User {
+			id: ID!
+			profile: NonExistentType1
+			settings: NonExistentType2
+		}
+	`
+
+	_, err := MergeSDLs(sdl)
+	require.Error(t, err)
+}
+
+func TestMergeSDLs_ListTypes(t *testing.T) {
+	sdl := `
+		type User {
+			id: ID!
+			tags: [String!]!
+			friends: [User!]
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "User")
+	assert.Contains(t, result, "tags")
+	assert.Contains(t, result, "friends")
+}
+
+func TestMergeSDLs_NonNullTypes(t *testing.T) {
+	sdl := `
+		type User {
+			id: ID!
+			name: String!
+			email: String
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "User")
+	assert.Contains(t, result, "id")
+	assert.Contains(t, result, "name")
+	assert.Contains(t, result, "email")
+}
+
+func TestMergeSDLs_Comments(t *testing.T) {
+	sdl := `
+		# This is a user type
+		type User {
+			# User ID
+			id: ID!
+			# User name
+			name: String!
+		}
+	`
+
+	result, err := MergeSDLs(sdl)
+	require.NoError(t, err)
+	assert.Contains(t, result, "User")
+}
+
+func TestMergeSDLs_LargeSchema(t *testing.T) {
+	// Test with a reasonably large schema to ensure performance
+	var sdlBuilder strings.Builder
+	for i := 0; i < 50; i++ {
+		sdlBuilder.WriteString("type Type")
+		sdlBuilder.WriteString(strings.Repeat(string(rune('A'+i%26)), 1))
+		sdlBuilder.WriteString(string(rune('0' + i/26)))
+		sdlBuilder.WriteString(" { id: ID }\n")
+	}
+
+	result, err := MergeSDLs(sdlBuilder.String())
+	require.NoError(t, err)
+
+	// Verify some types are present
+	assert.Contains(t, result, "TypeA0")
+	assert.Contains(t, result, "TypeB0")
+	assert.Contains(t, result, "TypeC0")
+}