public static UUnary create(Kind unaryOp, UExpression expression) {
    checkArgument(
        UNARY_OP_CODES.containsKey(unaryOp), "%s is not a recognized unary operation", unaryOp);
    return new AutoValue_UUnary(unaryOp, expression);
  }
@Test
  public void preIncrement() {
    assertUnifiesAndInlines("++foo", UUnary.create(Kind.PREFIX_INCREMENT, fooIdent));
  }