code: private static void checkPreconditions(final Class<?> jodaClass,
  			final String pattern) {
  		if (jodaClass == null) {
  			throw new NullPointerException("jodaClass should not be null");
  		} else if (pattern == null) {
  			throw new NullPointerException("pattern should not be null");
  		}
  	}
docs: Checks the preconditions for creating a new
  AbstractJodaFormattingProcessor processor.
  
  @param jodaClass
  the Joda class
  @param pattern
  the pattern
  @throws NullPointerException
  if jodaClass or pattern is null