For each use case above, draw the corresponding Use Case Diagram and the corresponding Sequence Diagram. Use operands in the sequence diagrams and stereotypes in the use case diagrams as you deem appropriate. For the first deliverable you can consider the following use cases: UC1: A user sends a placeOrder request to the system (i.e. the Welcome Proxy). The user needs to be authenticated. If the user is authenticated then his/her request is handled by the back-end system. Consider that there is a database with user credentials. The users can be authenticated using user name and password or just a PIN. In special cases can be authenticated by calling an agent on the phone