String toTest =
        MoreObjects.toStringHelper(new TestClass()).add("field1", Integer.valueOf(42)).toString();
    assertTrue(toTest, toTest.matches(".*\\{field1\\=42\\}"));
  }

  public void testToStringLenient_nullInteger() {
    String toTest =
        MoreObjects.toStringHelper(new TestClass()).add("field1", (Integer) null).toString();
    assertTrue(toTest, toTest.matches(".*\\{field1\\=null\\}"));
  }