two questions

Let us consider the WhatsApp messaging software by Meta. Users have variety of options to utilize the system on a day-to-day basis via its mobile, desktop, web and other devices (such iPad or Tablet). In this case study we shall focus on individual account holder as an actor. The following is the requirements statement you are to use in modeling the system: To use the messaging app, individual (may be referred to as a user) must set up an account with meta which may require providing name, eman address, and phone number. They can chat with their contacts (and view if the contact has viewed the chat). Every chat will have time and day of posting (if not the current day), and content (i.e., the associated text). In chats, they shall be allowed to send cmojis, video and audio files to their contacts. Users shall be able to call any contact either by making (a voice or video call) or decline any call they do not wish to pick. Each call will have the time initiated and when the call ended (to allow computation of call duration). If the individual chooses to turn off their video during a call, the app shall allow them to do so. They should also be allowed to turn on their videos as they wish. User can make/post a status update and delete an update. Each status update will have the time posted. A status update may be a picture or video (plus text), hence must be supported to browse the gallery to choose the media of choice. If any contact views the status, the user should be allowed to see the list of contacts who viewed their updates. User may set their display picture, and be allowed to choose a picture of their choice from the gallery. (a) Develop a use-case model for the system whose requirements is expressed above (use generalization, and extends and includes stereotypes where possible). (30 points) Hint: identify all user-interactions from the requirements statement and word them as actions into use cases. (b) Develop a class model for the system whose requirements is expressed above (use generalization, associations, multiplicities, role names, design patterns, among other modeling constructs, where possible). (20 points) Hint: identify all objects (and their attributes) from the requirements statement, and establish relationships between them. The analysis of a well-dereloped use case model will produce most of the classes. Note your assumptions (if any)