public static UTypeVar create(String name, UType lowerBound, UType upperBound) {
    return new UTypeVar(name, lowerBound, upperBound);
  }
@Test
  public void serialization() {
    UType nullType = UPrimitiveType.create(TypeKind.NULL);
    UType charSequenceType = UClassType.create("java.lang.CharSequence", ImmutableList.<UType>of());
    SerializableTester.reserializeAndAssert(UTypeVar.create("T", nullType, charSequenceType));
  }