public static void checkState(boolean b,  String errorMessageTemplate, char p1, int p2) {
    if (!b) {
      throw new IllegalStateException(format(errorMessageTemplate, p1, p2));
    }
  }
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.
common/util/src/main/java/io/apiman/common/util/Preconditions.java