   func testVisitConstantDeclaration() {
     let node = ConstantDeclaration(initializerList: [])
     do {
-      let result = try defaultVisitor.traverse(node)
+      let result = try defaultVisitor.traverse(node as Declaration)
       XCTAssertTrue(result)
     } catch {
       XCTFail("Failed in visiting ConstantDeclaration")

    let node = ExtensionDeclaration(
      type: TypeIdentifier(), typeInheritanceClause: nil)
    do {
      let result = try defaultVisitor.traverse(node)
      XCTAssertTrue(result)
    } catch {
      XCTFail("Failed in visiting ExtensionDeclaration")

  func testVisitInitializerDeclaration() {
    let node = InitializerDeclaration(body: CodeBlock())
    do {
      let result = try defaultVisitor.traverse(node as Declaration)
      XCTAssertTrue(result)
    } catch {
      XCTFail("Failed in visiting InitializerDeclaration")
