code: public long optLong(String name, long fallback) {
  		Object object = opt(name);
  		Long result = JSON.toLong(object);
  		return result != null ? result : fallback;
  	}
docs: Returns the value mapped by {@code name} if it exists and is a long or can be
  coerced to a long. Returns {@code fallback} otherwise. Note that JSON represents
  numbers as doubles, so this is <a href="#lossy">lossy</a>; use strings to transfer
  numbers via JSON.
  @param name the name of the property
  @param fallback a fallback value
  @return the value or {@code fallback}