Java question

A class named Serial Publication is defined as shown in the class diagram. It contains An enum/enumeration type named Frequency with the value of daily, weekly, monthly, quarterly, yearly and undefined. A protected instance variable frequency of type Frequency. Two constructors. One takes no parameter and sets the value of frequency to undefined. One takes a String parameter and uses the parameter to call the setFrequency() method. A setFrequency() method that takes a String parameter and sets the instance variable frequency to the matching value in the enum. If there is no matching value in the enum the method sets frequency to undefined. A getFrequency() method that returns the value of frequency in a lowercase String. Write the Serial Publication class in the answer box below