code: public final boolean evalBoolean(final Object object) throws IllegalArgumentException {
          final Boolean result = evalUnique(object, Boolean.class);
          return result == null ? false : result;
      }
docs: Evaluates this {@code XPath} expression on the object supplied, producing a boolean value
  as result.
  
  @param object
  the object to evaluate this expression on
  @return the boolean value resulting from the evaluation, on success; on failure, false is
  returned if this {@code XPath} expression is lenient
  @throws IllegalArgumentException
  if this {@code XPath} expression is not lenient and evaluation fails for the
  object supplied