Draw a class diagram to model the structural properties of the problem: A software company sells both products and services to customers. Products can be classified into system software and application package. All the products and services are marketed by sales executives. Each product is supported by a number of product specialists. Services can be classified into turnkey development, maintenance and facility management. All the services are organized as projects. Each project has a project team to work on it. A project team is formed by at least three staff members. One staff member from the project team, called project manager, manages the project. A staff member can be a project member of up to five projects. A project manager may manage multiple projects concurrently