Return true if this object is in a valid state, and false otherwise. Objects are in a valid state after construction from a valid set of option specifications (see the function‐level documentation of the isValidOptionSpecificationTable method) and after a successful invocation of the parse method. Conversely, construction from invalid option specifications or an unsuccessful invocation of the parse method leaves this object in an invalid state. Note that additional object state is available from the isParsed accessor method.