Class Diagrams $$ Consider the email system$($s$)$ that you use. Make $2$ class diagrams $($Attributes$,$ Operations$/$Methods$)$ for a Mail system. You should be able to come up with at least $5$ attributes and $4$ operations for each class. Since a mailbox contains messages, think about which attributes and operations belong to which class.

a$)$ Message class

b$)$ Mailbox class