Building a class diagram for a problem statement:

Draw a class diagram $($using DRAW.IO$)$

corresponds to the following problem:

An Employee has a name $($type String$),$ a social insurance number $($type Integer$),$ an address $($type String$),$ and a level $($type String$).$ An Employee can work on many Projects at once but has to work on at least one project at any time, each project being described by a project identifier $($type String$),$ a project name $($type String$),$ a start date $($type date$),$ an end date $($type date$),$ and a customer. Employee and customers are both Persons. Furthermore, an Employee works a specific number of hours $($type real$)$ on a project.