Design an ER diagram for the following application Clearly state the assumptions you make and justify your assumptions. The system needs to keep track of aircrafts, flight crews customers and their itineraries, and flights Each aircraft has a unique number, maker, model, and capacity. A crew member is either a flight attendant or a pilot. Each crew member has his/her employee ID name, job title, and base city. Each crew member serves several flights and each flight has two co-pilots and several flight attendants. Each customer has a profile (you will need to decide what information to keep) and may have several itineraries. Each itinerary consists of one or more flights Each flight has a unique flight number a departing city an arriving city a departing time, an arriving time, and number of available seats. Several aircrafts may fly under the same flight number on different days