   }
 
   func testOptionalBool() {
-    let userDefaults = UserDefaults.standard
+    let userDefaults = testDefaults!
     let key = "\(#function)\(#line)"
     XCTAssertFalse(userDefaults.hasKey(key))
 

  }

  func testOptionalDouble() {
    let userDefaults = UserDefaults.standard
    let key = "\(#function)\(#line)"
    XCTAssertFalse(userDefaults.hasKey(key))


  }

  func testOptionalFloat() {
    let userDefaults = testDefaults!
    let key = "\(#function)\(#line)"
    XCTAssertFalse(userDefaults.hasKey(key))

