code: public static void checkState(
        boolean b, @NullableDecl String errorMessageTemplate, @NullableDecl Object p1, int p2) {
      if (!b) {
        throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
      }
    }
docs: Ensures the truth of an expression involving the state of the calling instance, but not
  involving any parameters to the calling method.
  
  <p>See {@link #checkState(boolean, String, Object...)} for details.
  
  @since 20.0 (varargs overload since 2.0)